1.
Ruler
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A ruler, sometimes called a rule or line gauge, is an instrument used in geometry, technical drawing, printing, engineering and building to measure distances or to rule straight lines. The ruler is a straightedge which may also contain calibrated lines to measure distances, rulers have long been made from different materials and in a wide range of sizes. Plastics have also used since they were invented, they can be molded with length markings instead of being scribed. Metal is used for more durable rulers for use in the workshop,12 inches or 30 cm in length is useful for a ruler to be kept on a desk to help in drawing. Shorter rulers are convenient for keeping in a pocket, longer rulers, e. g.18 inches are necessary in some cases. Rigid wooden or plastic yardsticks,1 yard long, and meter sticks,1 meter long, are also used, classically, long measuring rods were used for larger projects, now superseded by tape measure or laser rangefinders. Desk rulers are used for three purposes, to measure, to aid in drawing straight lines and as a straight guide for cutting and scoring with a blade. Practical rulers have distance markings along their edges, a line gauge is a type of ruler used in the printing industry. These may be made from a variety of materials, typically metal or clear plastic, units of measurement on a basic line gauge usually include inches, agate, picas, and points. More detailed line gauges may contain sample widths of lines, samples of common type in several point sizes, measuring instruments similar in function to rulers are made portable by folding or retracting into a coil when not in use. When extended for use, they are straight, like a ruler, the illustrations on this page show a 2-meter carpenters rule, which folds down to a length of 24 cm to easily fit in a pocket, and a 5-meter-long tape, which retracts into a small housing. A flexible length measuring instrument which is not necessarily straight in use is the tailors fabric tape measure and it is used to measure around a solid body, e. g. a persons waist measurement, as well as linear measurement, e. g. inside leg. It is rolled up when not in use, taking up little space, a contraction rule is made having larger divisions than standard measures to allow for shrinkage of a metal casting. They may also be known as a shrinkage or shrink rule, a ruler software program can be used to measure pixels on a computer screen or mobile phone. These programs are known as screen rulers. In geometry, a ruler without any marks on it may be used only for drawing lines between points. A straightedge is used to help draw accurate graphs and tables. A ruler and compass construction refers to using an unmarked ruler
2.
Keychain
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A keychain, key fob or key ring is a small chain, usually made from metal or plastic, that connects a small item to a keyring. The length of a keychain allows an item to be used more easily than if connected directly to a keyring, some keychains allow one or both ends the ability to rotate, keeping the keychain from becoming twisted, while the item is being used. A keychain can also be a link between a keyring and the belt of an individual. It is usually employed by personnel whose job demands frequent use of keys, such as a security guard, prison officer, the chain is often retractable, and therefore may be a nylon rope, instead of an actual metal chain. The chain ensures that the keys attached to the individual using them, makes accidental loss less likely. Keychains are one of the most common souvenir and advertising items, keychains are commonly used to promote businesses. A standard advertising keychain will carry the name and contact information. In the 1950s and 1960s, with the improvement of manufacturing techniques. Businesses could place their names on promotional keychains that were three-dimensional for less cost than the standard metal keychains, keychains are small and inexpensive enough to become promotional items for larger national companies that might give them out by the millions. For example, with the launch of a new movie or television show, keychains that currently hold keys are an item that is never long misplaced by the owner. People sometimes attach their keychain to their belt to avoid loss or to allow access to it. Many keychains also offer functions that the owner wants easily accessible as well and these include an army knife, bottle opener, an electronic organizer, scissors, address book, family photos, nail clipper, pill case and even pepper spray. Modern cars often include a keychain that serves as a remote to lock/unlock the car or even start the engine, an electronic key finder is also a useful item found on many keys that will beep when summoned for quick finding when misplaced. A keyring or split ring is a ring that holds keys and other small items, other types of keyrings are made of leather, wood and rubber. Keyring was invented in the 19th century by Alexander Parkes, the most common form of the keyring is a single piece of metal in a double loop. Either end of the loop can be pried open to allow a key to be inserted, novelty carabiners are also commonly used as keyrings for ease of access and exchange. Often the keyring is adorned with a key fob for self-identification, other forms of rings may use a single loop of metal or plastic with a mechanism to open and securely close the loop. The word fob may be linked to the low German dialect for the word Fuppe, meaning pocket, however, fob pockets were pockets meant to deter thieves
3.
Novelty item
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A novelty item is an object which is specifically designed to serve no practical purpose, and is sold for its uniqueness, humor, or simply as something new. The term also applies to items with fanciful or nonfunctional additions. The term is applied to small objects, and is generally not used to describe larger items such as roadside attractions. Items may have an advertising or promotional purpose, or be a souvenir and this term covers a range of small manufactured goods, such as collectables, gadgets and executive toys. Novelty items are generally devices that do not primarily have a practical function, toys for adults are often classed as novelties. Some products have a period as a novelty item when they are actually new, only to become an established, commonly used product. Others may have an element, such as Crookes radiometer, Newtons cradle or the drinking bird. Sex toys are described as novelty items, and some products sold in sex shops may not have any practical sexual function, if operating primarily as a humorous gift. Some food products may be considered novelty items, especially when first introduced, the French mathematician and astronomer Pierre Hérigone describes a novelty item that was a camera obscura in the form of a goblet. Hérigones device was constructed in such a way that you could spy on others while taking a drink and its 45-degree mirror had a stylized opening for the lens and the lid bore a magnifying lens at the top. Lenticular printing was developed in the 1940s, and is used extensively in the production of novelty items, paper clothing, which has some practical purpose, was briefly novel in the United States in the 1960s. One of the popular novelty items in recent history was the singing Big Mouth Billy Bass. It is estimated that over 20 million original pieces were sold in 12 months during 2000 and 2001, novelty items based on mathematical objects that cannot exist, such as Klein bottles, and Penrose triangles, have been manufactured. Models of Moebius Strips, which can exist, are made in place of regular bands
4.
Surveying
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Surveying or land surveying is the technique, profession, and science of determining the terrestrial or three-dimensional position of points and the distances and angles between them. A land surveying professional is called a land surveyor, Surveyors work with elements of geometry, trigonometry, regression analysis, physics, engineering, metrology, programming languages and the law. Surveying has been an element in the development of the environment since the beginning of recorded history. The planning and execution of most forms of construction require it and it is also used in transport, communications, mapping, and the definition of legal boundaries for land ownership. It is an important tool for research in other scientific disciplines. Basic surveyance has occurred since humans built the first large structures, the prehistoric monument at Stonehenge was set out by prehistoric surveyors using peg and rope geometry. In ancient Egypt, a rope stretcher would use simple geometry to re-establish boundaries after the floods of the Nile River. The almost perfect squareness and north-south orientation of the Great Pyramid of Giza, built c.2700 BC, the Groma instrument originated in Mesopotamia. The mathematician Liu Hui described ways of measuring distant objects in his work Haidao Suanjing or The Sea Island Mathematical Manual, the Romans recognized land surveyors as a profession. They established the basic measurements under which the Roman Empire was divided, Roman surveyors were known as Gromatici. In medieval Europe, beating the bounds maintained the boundaries of a village or parish and this was the practice of gathering a group of residents and walking around the parish or village to establish a communal memory of the boundaries. Young boys were included to ensure the memory lasted as long as possible, in England, William the Conqueror commissioned the Domesday Book in 1086. It recorded the names of all the owners, the area of land they owned, the quality of the land. It did not include maps showing exact locations, abel Foullon described a plane table in 1551, but it is thought that the instrument was in use earlier as his description is of a developed instrument. Gunters chain was introduced in 1620 by English mathematician Edmund Gunter and it enabled plots of land to be accurately surveyed and plotted for legal and commercial purposes. Leonard Digges described a Theodolite that measured horizontal angles in his book A geometric practice named Pantometria, joshua Habermel created a theodolite with a compass and tripod in 1576. Johnathon Sission was the first to incorporate a telescope on a theodolite in 1725, in the 18th century, modern techniques and instruments for surveying began to be used. Jesse Ramsden introduced the first precision theodolite in 1787 and it was an instrument for measuring angles in the horizontal and vertical planes
5.
Hectometre
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The hectometre or hectometer is an uncommonly used unit of length in the metric system, equal to one hundred metres. It derives from the Greek word ekato, meaning hundred, a soccer field is approximately 1 hectometre in length. The hectare, a metric unit for land area, is equal to one square hectometre
6.
Sewing
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Sewing is the craft of fastening or attaching objects using stitches made with a needle and thread. Sewing is one of the oldest of the arts, arising in the Paleolithic era. For thousands of years, all sewing was done by hand, fine hand sewing is a characteristic of high-quality tailoring, haute couture fashion, and custom dressmaking, and is pursued by both textile artists and hobbyists as a means of creative expression. The first known use of the sewing was in the 14th century. Sewing has an ancient history estimated to begin during the Paleolithic Age, Sewing was used to stitch together animal hides for clothing and for shelter. The weaving of cloth from natural fibres originated in the Middle East around 4000 BCE, and perhaps earlier during the Neolithic Age, during the Middle Ages, Europeans who could afford it employed seamstresses and tailors. Sewing for the most part was an occupation, and most sewing before the 19th century was practical. Clothing was an investment for most people, and women had an important role in extending the longevity of items of clothing. Clothing that was faded would be turned inside-out so that it could continue to be worn, once clothing became worn or torn, it would be taken apart and the reusable cloth sewn together into new items of clothing, made into quilts, or otherwise put to practical use. The many steps involved in making clothing from scratch meant that women often bartered their expertise in a skill with one another. Decorative needlework such as embroidery was a skill, and young women with the time. From the Middle Ages to the 17th century, sewing tools such as needles, decorative embroidery was valued in many cultures worldwide. Some examples are the Cretan Open Filling stitch, Romanian Couching or Oriental Couching, the stitches associated with embroidery spread by way of the trade routes that were active during the Middle Ages. European imperial settlements also spread embroidery and sewing techniques worldwide, however, there are instances of sewing techniques indigenous to cultures in distant locations from one another, where cross-cultural communication would have been historically unlikely. For example, a method of reverse appliqué known to areas of South America is also known to Southeast Asia, the Industrial Revolution shifted the production of textiles from the household to the mills. In the early decades of the Industrial Revolution, the machinery produced whole cloth, the worlds first sewing machine was patented in 1790 by Thomas Saint. By the early 1840s, other early sewing machines began to appear, by the 1850s, Isaac Singer developed the first sewing machines that could operate quickly and accurately and surpass the productivity of a seamstress or tailor sewing by hand. While much clothing was produced at home by female members of the family
7.
Carpentry
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Carpentry in the United States is almost always done by men. With 98. 5% of carpenters being male, it was the fourth most male-dominated occupation in the country in 1999, Carpenters are usually the first tradesmen on a job and the last to leave. Carpenters normally framed post-and-beam buildings until the end of the 19th century and it is also common that the skill can be learned by gaining work experience other than a formal training program, which may be the case in many places. The word carpenter is the English rendering of the Old French word carpentier which is derived from the Latin carpentrius, the Middle English and Scots word was wright, which could be used in compound forms such as wheelwright or boatwright. An easy way to envisage this is that first fix work is all that is done before plastering takes place, second fix is done after plastering takes place. Second fix work, the construction of such as skirting boards, architraves. Carpentry is also used to construct the formwork into which concrete is poured during the building of such as roads. In the UK, the skill of making timber formwork for poured, or in situ, although the. work of a carpenter and joiner are often combined. Joiner is less common than the finish carpenter or cabinetmaker. The terms housewright and barnwright were used historically, now used by carpenters who work using traditional methods. Someone who builds custom concrete formwork is a form carpenter, wood is one of mankinds oldest building materials. The ability to shape wood improved with technological advances from the age to the bronze age to the iron age. The oldest surviving, complete text is Vitruvius ten books collectively titled De architectura which discusses some carpentry. By the 16th century sawmills were coming into use in Europe, the founding of America was partly based on a desire to extract resources from the new continent including wood for use in ships and buildings in Europe. In the 18th century part of the Industrial Revolution was the invention of the steam engine and these technologies combined with the invention of the circular saw led to the development of balloon framing which was the beginning of the decline of traditional timber framing. The 19th century saw the development of engineering and distribution which allowed the development of hand-held power tools, wire nails. In the 20th century portland cement came into use and concrete foundations allowed carpenters to do away with heavy timber sills. Also, drywall came into common use replacing lime plaster on wooden lath, plywood, engineered lumber and chemically treated lumber also came into use
8.
Ancient Rome
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In its many centuries of existence, the Roman state evolved from a monarchy to a classical republic and then to an increasingly autocratic empire. Through conquest and assimilation, it came to dominate the Mediterranean region and then Western Europe, Asia Minor, North Africa and it is often grouped into classical antiquity together with ancient Greece, and their similar cultures and societies are known as the Greco-Roman world. Ancient Roman civilisation has contributed to modern government, law, politics, engineering, art, literature, architecture, technology, warfare, religion, language and society. Rome professionalised and expanded its military and created a system of government called res publica, the inspiration for modern republics such as the United States and France. By the end of the Republic, Rome had conquered the lands around the Mediterranean and beyond, its domain extended from the Atlantic to Arabia, the Roman Empire emerged with the end of the Republic and the dictatorship of Augustus Caesar. 721 years of Roman-Persian Wars started in 92 BC with their first war against Parthia and it would become the longest conflict in human history, and have major lasting effects and consequences for both empires. Under Trajan, the Empire reached its territorial peak, Republican mores and traditions started to decline during the imperial period, with civil wars becoming a prelude common to the rise of a new emperor. Splinter states, such as the Palmyrene Empire, would divide the Empire during the crisis of the 3rd century. Plagued by internal instability and attacked by various migrating peoples, the part of the empire broke up into independent kingdoms in the 5th century. This splintering is a landmark historians use to divide the ancient period of history from the pre-medieval Dark Ages of Europe. King Numitor was deposed from his throne by his brother, Amulius, while Numitors daughter, Rhea Silvia, because Rhea Silvia was raped and impregnated by Mars, the Roman god of war, the twins were considered half-divine. The new king, Amulius, feared Romulus and Remus would take back the throne, a she-wolf saved and raised them, and when they were old enough, they returned the throne of Alba Longa to Numitor. Romulus became the source of the citys name, in order to attract people to the city, Rome became a sanctuary for the indigent, exiled, and unwanted. This caused a problem for Rome, which had a large workforce but was bereft of women, Romulus traveled to the neighboring towns and tribes and attempted to secure marriage rights, but as Rome was so full of undesirables they all refused. Legend says that the Latins invited the Sabines to a festival and stole their unmarried maidens, leading to the integration of the Latins, after a long time in rough seas, they landed at the banks of the Tiber River. Not long after they landed, the men wanted to take to the sea again, one woman, named Roma, suggested that the women burn the ships out at sea to prevent them from leaving. At first, the men were angry with Roma, but they realized that they were in the ideal place to settle. They named the settlement after the woman who torched their ships, the Roman poet Virgil recounted this legend in his classical epic poem the Aeneid
9.
Stanley Black & Decker
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Stanley Black & Decker, Inc. Stanley Black & Decker is the result of the merger of Stanley Works and Black & Decker on March 12,2010. During World War II, Stanley Works received the Army-Navy E Award for excellence in war production, in May 2002, the company considered moving its corporate headquarters to Bermuda, but public and governmental outcry forced management to reconsider the move. By August 2002, the company had decided to maintain its incorporation in the United States, John F. Lundgren was elected as chairman and chief executive officer in 2004, replacing John Trani, a former protégé of Jack Welch at General Electric. 1937, Stanley Works entered the UK market with the acquisition of J. A Chapman of Sheffield,1946, Stanley Works acquired North Brothers Manufacturing Company. 1963, Stanley started operations in Australia as Stanley-Titan when it bought a 50% share of Titan,1966, Stanley Works acquired Vidmar Cabinets. 1970, Stanley-Titan acquired Turner Tools based in Melbourne, Australia,1980, Stanley Works acquired Mac Tools. 1984, Stanley Works purchased Proto from Ingersoll Rand and it becomes Stanley Proto,1986, Stanley Works acquired Bostitch from Textron. 1990, Stanley Works acquired Goldblatt and ZAG Industries,1992, Stanley Works purchased the Chatsworth, California-based Monarch Mirror Door Co. Inc. an American manufacturer of sliding and folding mirror-doors. 2000, Stanley Works acquired Blick of Swindon, England, a UK integrator of security solutions, communication, and time-management solutions,2002, In October, Stanley Works acquired Best Access Systems of Indianapolis, Indiana, for $310 million. The acquisition also prompted the creation of a new Access Controls Group for Stanley, further additions to this new working group included Blick. 2004, In January, Stanley announced plans to acquire Frisco Bay Industries Ltd. a Canadian provider of security integration services, in December, the acquisition of ISR Solutions, Inc. headquartered in Washington, D. C. was announced. ISR Solutions provides the U. S. federal government and commercial customers with access security system services,2005, In January, the acquisition of Security Group, Inc. was announced. An additional acquisition of Precision Hardware was made in 2005, in the meantime, the company obtained security contracts as the primary contractor to secure three NASA spaceflight centers. 2008, Stanley acquired Beach Toolbox Industries, headquartered in Smith Falls, Ontario, Canada,2008, In June, Stanley announced the acquisition of Sonitrol, which provides security systems that use audio listening devices as the primary means of intrusion detection. Stanley also acquired Xmark Corporation, which radio frequency identification solutions in healthcare environments. As of 2008, many of the Stanley Security Services divisions were being integrated under the HSM brand,2009, On November 2, Stanley announced a merger with Black & Decker. The merger was completed on March 12,2010,2010, In July, the company announced the acquisition of CRC-Evans Pipeline International. CRC-Evans provides total project support for construction contractors with automatic welding and other pipeline construction specific equipment
10.
Integrated circuit
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An integrated circuit or monolithic integrated circuit is a set of electronic circuits on one small flat piece of semiconductor material, normally silicon. The ICs mass production capability, reliability and building-block approach to circuit design ensured the rapid adoption of standardized ICs in place of using discrete transistors. ICs are now used in all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones, and other home appliances are now inextricable parts of the structure of modern societies, made possible by the small size. These advances, roughly following Moores law, allow a computer chip of 2016 to have millions of times the capacity, ICs have two main advantages over discrete circuits, cost and performance. Cost is low because the chips, with all their components, are printed as a unit by photolithography rather than being constructed one transistor at a time, furthermore, packaged ICs use much less material than discrete circuits. Performance is high because the ICs components switch quickly and consume little power because of their small size, the main disadvantage of ICs is the high cost to design them and fabricate the required photomasks. This high initial cost means ICs are only practical when high production volumes are anticipated, Circuits meeting this definition can be constructed using many different technologies, including thin-film transistor, thick film technology, or hybrid integrated circuit. However, in general usage integrated circuit has come to refer to the single-piece circuit construction originally known as a integrated circuit. Jacobi disclosed small and cheap hearing aids as typical industrial applications of his patent, an immediate commercial use of his patent has not been reported. The idea of the circuit was conceived by Geoffrey Dummer. Dummer presented the idea to the public at the Symposium on Progress in Quality Electronic Components in Washington and he gave many symposia publicly to propagate his ideas, and unsuccessfully attempted to build such a circuit in 1956. A precursor idea to the IC was to create small ceramic squares, Components could then be integrated and wired into a bidimensional or tridimensional compact grid. This idea, which seemed very promising in 1957, was proposed to the US Army by Jack Kilby, however, as the project was gaining momentum, Kilby came up with a new, revolutionary design, the IC. In his patent application of 6 February 1959, Kilby described his new device as a body of semiconductor material … wherein all the components of the circuit are completely integrated. The first customer for the new invention was the US Air Force, Kilby won the 2000 Nobel Prize in Physics for his part in the invention of the integrated circuit. His work was named an IEEE Milestone in 2009, half a year after Kilby, Robert Noyce at Fairchild Semiconductor developed his own idea of an integrated circuit that solved many practical problems Kilbys had not. Noyces design was made of silicon, whereas Kilbys chip was made of germanium, Noyce credited Kurt Lehovec of Sprague Electric for the principle of p–n junction isolation, a key concept behind the IC
11.
Laser
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A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term laser originated as an acronym for light amplification by stimulated emission of radiation, the first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light coherently, spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances, Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i. e. they can emit a single color of light. Temporal coherence can be used to produce pulses of light as short as a femtosecond, Lasers are distinguished from other light sources by their coherence. Spatial coherence is typically expressed through the output being a narrow beam, Laser beams can be focused to very tiny spots, achieving a very high irradiance, or they can have very low divergence in order to concentrate their power at a great distance. Temporal coherence implies a polarized wave at a single frequency whose phase is correlated over a great distance along the beam. A beam produced by a thermal or other incoherent light source has an amplitude and phase that vary randomly with respect to time and position. Lasers are characterized according to their wavelength in a vacuum, most single wavelength lasers actually produce radiation in several modes having slightly differing frequencies, often not in a single polarization. Although temporal coherence implies monochromaticity, there are lasers that emit a broad spectrum of light or emit different wavelengths of light simultaneously, there are some lasers that are not single spatial mode and consequently have light beams that diverge more than is required by the diffraction limit. However, all devices are classified as lasers based on their method of producing light. Lasers are employed in applications where light of the spatial or temporal coherence could not be produced using simpler technologies. The word laser started as an acronym for light amplification by stimulated emission of radiation, in the early technical literature, especially at Bell Telephone Laboratories, the laser was called an optical maser, this term is now obsolete. A laser that produces light by itself is technically an optical rather than an optical amplifier as suggested by the acronym. It has been noted that the acronym LOSER, for light oscillation by stimulated emission of radiation. With the widespread use of the acronym as a common noun, optical amplifiers have come to be referred to as laser amplifiers. The back-formed verb to lase is frequently used in the field, meaning to produce light, especially in reference to the gain medium of a laser. Further use of the laser and maser in an extended sense, not referring to laser technology or devices, can be seen in usages such as astrophysical maser
12.
Mickey Mantle
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Mickey Charles Mantle, nicknamed The Commerce Comet and The Mick, was an American professional baseball player. Mantle played his entire Major League Baseball career with the New York Yankees as a fielder and first baseman. Mantle was one of the best players and sluggers, and is regarded by many as the greatest switch hitter in baseball history, Mantle was inducted into the National Baseball Hall of Fame in 1974 and was elected to the Major League Baseball All-Century Team in 1999. Mantle was arguably the greatest offensive threat of any center fielder in baseball history and he has the highest career OPS+ of any center fielder and he had the highest stolen base percentage in history at the time of his retirement. He also had an excellent 0.984 fielding percentage when playing center field, Mantle was noted for his ability to hit for both average and power, especially tape measure home runs. He hit 536 MLB career home runs, batted.300 or more ten times, Mantle won the Triple Crown in 1956, leading the major leagues in batting average, home runs, and runs batted in, he later wrote a book about his best year in baseball. He was an All-Star for 16 seasons, playing in 16 of the 20 All-Star Games that were played and he was an American League Most Valuable Player three times and a Gold Glove winner once. Mantle appeared in 12 World Series including seven championships, and holds World Series records for the most home runs, RBIs, extra-base hits, runs, walks, and total bases. Mantle was born on October 20,1931 in Spavinaw, Oklahoma and he was of at least partial English ancestry, his great-grandfather, George Mantle, left Brierley Hill, in Englands Black Country, in 1848. Mutt named his son in honor of Mickey Cochrane, a Hall of Fame catcher, later in his life, Mantle expressed relief that his father had not known Cochranes true first name, as he would have hated to be named Gordon. Mantle spoke warmly of his father, and said he was the bravest man he ever knew, No boy ever loved his father more, he said. His grandfather died at the age of 60 in 1944, when Mantle was four years old, his family moved to the nearby town of Commerce, Oklahoma, where his father worked in lead and zinc mines. As a teenager, Mantle rooted for the St. Louis Cardinals, Mantle was an all-around athlete at Commerce High School, playing basketball as well as football in addition to his first love, baseball. His football playing nearly ended his athletic career, kicked in the left shin during a practice game during his sophomore year, Mantle developed osteomyelitis in his left ankle, a crippling disease that was incurable just a few years earlier. Mantle began his baseball career in Kansas with the semi-professional Baxter Springs Whiz Kids. In 1948, Yankees scout Tom Greenwade came to Baxter Springs to watch Mantles teammate, during the game, Mantle hit three home runs. Greenwade returned in 1949, after Mantles high school graduation, to sign Mantle to a league contract. Mantle signed for $140 per month with a $1,500 signing bonus, Mantle was assigned to the Yankees Class-D Independence Yankees of the Kansas–Oklahoma–Missouri League, where he played shortstop
13.
Joist
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In architecture and in structural engineering, a joist is one of a series of horizontal members supporting a ceiling or floor. Joists are supported by foundations, wall framing, or beams, joists are often laid out in repetitive patterns, much like the ribs of a human body. The intent of the use of type of framing is to span over an open space below the members. When incorporated into a framing system, the joists also serve to provide stiffness to the subfloor sheathing, allowing it to function as a horizontal diaphragm. Joists are often doubled or tripled, placed side by side, joists are either made of wood, engineered wood, or steel, each of which have unique characteristics. Typically, wood joists have the section of a plank with the longer faces positioned vertically. However, engineered wood joists may have a cross resembling the Roman capital letter I. Steel joists can take on shapes, resembling the Roman capital letters C, I, L and S. For historical reference, look into the use of wood joists in old-style timber framing, the invention of the circular saw for use in modern sawmills has made it possible to fabricate wood joists as dimensional lumber. Joists must exhibit the strength to support the load over a long period of time. In more developed countries such as the United States, the fabrication and installation of all framing members including joists must meet building code standards. Considering the cross section of a typical joist, the depth of the joist is critical in establishing a safe. The wider the spacing between the joists, the deeper the joist will need to be to stress and deflection under load. Lateral support called dwang, blocking, or strutting increases its stability, many steel joist manufacturers supply load tables in order to allow designers to select the proper joist sizes for their projects. Standard dimensional lumber joists have their limitations due to the limits of what farmed lumber can provide, the term binding joist is sometimes used to describe beams at floor level running perpendicular to the ridge of a gable roof and joined to the intermediate posts. Joists which land on a binding joist are called bridging joists, a large beam in the ceiling of a room carrying joists is a summer beam. A ceiling joist may be installed flush with the bottom of the beam or sometimes below the beam, joists left exposed and visible from below are called naked flooring or articulated and were typically planed smooth and sometimes chamfered or beaded. Joists may also be tenoned in during the raising with a tenon or a tusk tenon
14.
Timber roof truss
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A timber roof truss is a structural framework of timbers designed to bridge the space above a room and to provide support for a roof. Trusses usually occur at intervals, linked by longitudinal timbers such as purlins. The space between each truss is known as a bay, Timber roof trusses were a medieval development. Earlier roofs had been supported by coupled rafters – pairs of rafters linked by horizontal beams, but such roofs were structurally weak, and lacking any longitudinal support were prone to racking, a collapse resulting from horizontal movement. The top members of a truss are known generically as the top chord, bottom members as the chord. In historic carpentry the top chords are called rafters. The terms closed truss and open truss are used in two ways to describe characteristics of truss roofs, closed truss, 1) A truss with a tie beam, 2) a roof system with a ceiling so the framing is not visible. Open truss, 1) A truss with a tie beam or scissor truss which allow a vaulted ceiling area, 2) Roof framing open to view. A king post truss has two principal rafters, a tie beam, and a central king post. The simplest of trusses, it is used in conjunction with two angled struts. The king post is normally under tension, and requires quite sophisticated joints with the tie beam, in a variation known as a king bolt truss the king post is replaced by a metal bolt, usually of wrought iron. A queen post truss has two principal rafters and two vertical queen posts, the queen post truss extends the span, and combined with spliced joints in the longer members extends the useful span for trusses of these types. As with a king post, the posts may be replaced with iron rods. This truss is known as a palladiana in Italy, as it was frequently used by the Venetian architect Andrea Palladio. Sometimes a palladian truss is defined as a truss with a queen post. The queen post truss and the king post truss may be combined, such combinations are known as compound trusses. Liegender stuhl is a truss of German origin, the German name is used in America and this truss is found in some 18th and 19th-century buildings where Germans settled in the U. S. The literal translation is lying chair, lying meaning the top chords are angled or leaning and chair in the sense of a support, carpenters in the Netherlands also used this truss where it is spelled liggende stoel
15.
Wall stud
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A wall stud is a vertical framing member in a buildings wall of smaller cross section than a post. They are an element in frame building. Stud is an ancient word related to words in Old English, Old Norse, Middle High German. Other historical words with similar meaning are quarter and scantling, stick is a colloquial term for both framing lumber and a timber tree. Thus the names stick and platform, stick and frame, stick and box, the stud height usually determines the ceiling height thus sayings like. These rooms were usually high in stud. Studs form walls and may carry vertical structural loads or be non load-bearing such as in partition walls which only separate spaces and they hold in place the windows, doors, interior finish, exterior sheathing or siding, insulation and utilities and help give shape to a building. Studs run from sill plate to wall plate, in modern construction studs are fastened to the plates in a way, such as using ties, to prevent the building from being lifted off the foundation by severe wind or earthquake. Studs are usually slender so more studs are needed than in post, sometimes studs are long, as in balloon framing where the studs extend two stories and carry a ledger which carries joists. Being thinner and lighter, stick construction techniques are easier to cut, in the United States studs were traditionally made of wood, usually 2×4 or 2×6 dimensional lumber and typically placed 16 inches from each others center, but sometimes also at 12 inches or 24 inches. The wood needs to be dry when used or problems may occur as the studs shrink, steel studs are gaining popularity, especially for non load-bearing walls, and are required in some firewalls. Posts in walls are used at point loads such as long spans near a window or sliding door. A building technique mostly associated with Lincolnshire, England, and parts of Scotland gets part of its name from the studs and this building method uses studs in a framework which is then totally covered with mud which resembles the building material cob. Another traditional building method is called stud and plaster where the walls are held by lath on the studs. Studs are also the namesake of a type of timber framing called close studding, based on the American West Coast Lumber Inspection Bureau grading rules, there is only one grade of stud, STUD. A stud is graded for vertical application and its stress requirements, a stud is most similar to a #2 grade, which is held to a higher standard during grading. The biggest difference between the two is the frequency, placement and size of knots and overall allowable wane
16.
Construction
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Construction is the process of constructing a building or infrastructure. Construction as an industry comprises six to nine percent of the domestic product of developed countries. Construction starts with planning, design, and financing, and continues until the project is built, large-scale construction requires collaboration across multiple disciplines. An architect normally manages the job, and a manager, design engineer. For the successful execution of a project, effective planning is essential, the largest construction projects are referred to as megaprojects. Construction is a term meaning the art and science to form objects, systems, or organizations. Construction is used as a verb, the act of building, and a noun, how a building was built, in general, there are three sectors of construction, buildings, infrastructure and industrial. Building construction is further divided into residential and non-residential. Infrastructure is often called heavy/highway, heavy civil or heavy engineering and it includes large public works, dams, bridges, highways, water/wastewater and utility distribution. Industrial includes refineries, process chemical, power generation, mills, there are other ways to break the industry into sectors or markets. Engineering News-Record is a magazine for the construction industry. Each year, ENR compiles and reports on data about the size of design and they publish a list of the largest companies in the United States and also a list the largest global firms. In 2014, ENR compiled the data in nine market segments and it was divided as transportation, petroleum, buildings, power, industrial, water, manufacturing, sewer/waste, telecom, hazardous waste plus a tenth category for other projects. In their reporting on the Top 400, they used data on transportation, sewer, hazardous waste, the Standard Industrial Classification and the newer North American Industry Classification System have a classification system for companies that perform or otherwise engage in construction. To recognize the differences of companies in this sector, it is divided into three subsectors, building construction, heavy and civil engineering construction, and specialty trade contractors, there are also categories for construction service firms and construction managers. Building construction is the process of adding structure to real property or construction of buildings, the majority of building construction jobs are small renovations, such as addition of a room, or renovation of a bathroom. Often, the owner of the property acts as laborer, paymaster, for this reason, those with experience in the field make detailed plans and maintain careful oversight during the project to ensure a positive outcome. Residential construction practices, technologies, and resources must conform to local building authority regulations, materials readily available in the area generally dictate the construction materials used
17.
Plywood
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Plywood is a sheet material manufactured from thin layers or plies of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is a wood from the family of manufactured boards which includes medium-density fibreboard. All plywoods bind resin and wood fibre sheets to form a composite material, there is usually an odd number of plies, so that the sheet is balanced—this reduces warping. Because plywood is bonded with grains running against one another and with an odd number of composite parts, the word ply derives from the French verb plier, to fold, from the Latin verb plico, from the ancient Greek verb πλέκω. In 1797 Samuel Bentham applied for patents covering several machines to produce veneers, in his patent applications, he described the concept of laminating several layers of veneer with glue to form a thicker piece – the first description of what we now call plywood. Samuel Bentham was a British naval engineer with many shipbuilding inventions to his credit. Veneers at the time of Bentham were flat sawn, rift sawn or quarter sawn, i. e. cut along or across the log manually in different angles to the grain and thus limited in width and length. One can thus presume that rotary lathe plywood manufacture was a process in France in the 1860s. Plywood was introduced into the United States in 1865 and industrial production started shortly after, in 1928, the first standard-sized 4 ft by 8 ft plywood sheets were introduced in the United States for use as a general building material. Artists use plywood as a support for paintings to replace traditional canvas or cardboard. Ready-made artist boards for oil painting in three-layered plywood were produced, in India, plywood is more commonly called Kitply after a leading brand which pioneered the concept of waterproof plywood in the early 1970s. A typical plywood panel has face veneers of a higher grade than the core veneers, the principal function of the core layers is to increase the separation between the outer layers where the bending stresses are highest, thus increasing the panels resistance to bending. As a result, thicker panels can span greater distances under the same loads, in bending, the maximum stress occurs in the outermost layers, one in tension, the other in compression. Bending stress decreases from the maximum at the layers to nearly zero at the central layer. Shear stress, by contrast, is higher in the center of the panel, the most common dimension is 1.2 by 2.4 metres or the slightly larger imperial dimension of 4 feet ×8 feet. Plies vary in thickness from 1.4 mm to 4.3 mm, the number of plies—which is always odd—depends on the thickness and grade of the sheet. Roofing can use the thinner 5/8 plywood, subfloors are at least 3/4 thick, the thickness depending on the distance between floor joists. T&G plywood is usually found in the 1/2 to 1 range, hardwood plywood is made out of wood from angiosperm trees and used for demanding end uses
18.
Drywall
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Drywall is a panel made of calcium sulfate dihydrate with or without additives and normally pressed between a facer and a backer. It is used to make walls and ceilings. The plaster is mixed with fibre, plasticizer, foaming agent, and various additives that can decrease mildew, increase fire resistance, drywall construction became prevalent in North America as a speedier alternative to traditional lath and plaster. The first plasterboard plant in the UK was opened in 1888 in Rochester, Sackett Board was invented in 1894 by Augustine Sackett and Fred Kane. It was made by layering plaster within four plies of wool felt paper, sheets were 36 ×36 × 1/4 thick with open edges. Gypsum board evolved between 1910 and 1930 beginning with wrapped board edges and elimination of the two layers of felt paper in favor of paper-based facings. In 1910 United States Gypsum Corporation bought Sackett Plaster Board Company, providing efficiency of installation, it was developed additionally as a measure of fire resistance. Later air entrainment technology made boards lighter and less brittle, then joint treatment materials, rock lath was an early substrate for plaster. As it evolved, it was faced with paper impregnated with gypsum crystals that bonded with the applied facing layer of plaster, a wallboard panel consists of a layer of gypsum plaster sandwiched between two layers of paper. The raw gypsum, CaSO4·2 H2O, is heated to drive off the water then slightly rehydrated to produce the hemihydrate of calcium sulfate, the board is then formed by sandwiching a core of the wet mixture between two sheets of heavy paper or fibreglass mats. When the core sets it is dried in a large drying chamber. Drying chambers typically use natural gas today, to dry 1 MSF of wallboard, between 1,750,000 and 2,490,000 BTU is required. Organic dispersants/plasticisers are used so the slurry will flow during manufacture, coal-fired power stations include devices called scrubbers to remove sulphur from their exhaust emissions. The sulphur is absorbed by powdered limestone in a process called flue-gas desulphurization and this is commonly used in drywall construction in the United States and elsewhere. Drywall panels in the United States are manufactured in 48-inch, 54-inch and 96-inch wide panels in varying lengths to suit the application, lengths up to 12-feet are commonly available, though the most common length is 8-feet. Common panel thicknesses are 1⁄2-inch and 5⁄8-inch, with panels also available in 1⁄4-inch, 3⁄8-inch, 3/4-inch and 1-inch for specific applications, in Europe plasterboard is manufactured in metric sizes, with the common sizes being corollaries of old imperial sizes. Most plasterboard is made in 120 cm-wide sheets, though 90 cm and 60 cm wide sheets are also made,120 cm wide plasterboard is most commonly made in 240 cm lengths, though 250,260,270,280,300 cm and even longer are commonly available. Thicknesses of plasterboard available are 9.5 mm to 25 mm, however four side chamfered drywall is not currently offered by major UK manufacturers for general use
19.
Particle board
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Oriented strand board, also known as flakeboard, waferboard, or chipboard, is similar but uses machined wood flakes offering more strength. All of these are composite materials that belong to the spectrum of fiberboard products, particle board is cheaper, denser and more uniform than conventional wood and plywood and is substituted for them when cost is more important than strength and appearance. However, particleboard can be more attractive by painting or the use of wood veneers onto surfaces that will be visible. Though it is denser than conventional wood, it is the lightest and weakest type of fiberboard, medium-density fibreboard and hardboard, also called high-density fiberboard, are stronger and denser than particleboard. Different grades of particleboard have different densities, with higher density connoting greater strength, a major disadvantage of particleboard is that it is very prone to expansion and discoloration due to moisture, particularly when it is not covered with paint or another sealer. The advantages of using particleboard over veneer core plywood is it is stable, much cheaper to buy. Firstly produced particleboard is dated back to 1887, when Hubbard made so-called artificial wood made from flour and albumin based adhesive. The first commercial piece was produced during World War II at a factory in Bremen, for its production, waste material was used - such as planer shavings, offcuts or sawdust - hammer-milled into chips and bound together with a phenolic resin. Hammer-milling involves smashing material into smaller and smaller pieces until they can pass through a screen, most other early particleboard manufacturers used similar processes, though often with slightly different resins. It was found that better strength, appearance and resin economy could be achieved by using more uniform and this type of board is known as three-layer particleboard. More recently, graded-density particleboard has also evolved, the raw material to be used for the particles is fed into a disc chipper with between four and sixteen radially arranged blades. The particles are then dried, after which any oversized or undersized particles are screened out, resin is then mist-sprayed through fine nozzles onto the particles. There are several types of resins that are commonly used, amino-formaldehyde based resins are the best performing when considering cost and ease of use. Urea Melamine resins are used to water resistance with increased melamine offering enhanced resistance. It is typically used where the panel is used in external applications due to the water resistance offered by phenolic resins. Melamine Urea phenolic formaldehyde resins exist as a compromise, the particles then pass through a mist of resin sufficient to coat all surfaces and are then layered, first into a continuous carpet. This carpet is then separated into discrete, rectangular blankets which will then be compacted in a cold press, a weighing device notes the weight of flakes, and they are distributed into position by rotating rakes. In graded-density particleboard, the flakes are spread by an air jet that throws finer particles further than coarse ones, two such jets, reversed, allow the particles to build up from fine to coarse and back to fine
20.
Canada
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Canada is a country in the northern half of North America. Canadas border with the United States is the worlds longest binational land border, the majority of the country has a cold or severely cold winter climate, but southerly areas are warm in summer. Canada is sparsely populated, the majority of its territory being dominated by forest and tundra. It is highly urbanized with 82 per cent of the 35.15 million people concentrated in large and medium-sized cities, One third of the population lives in the three largest cities, Toronto, Montreal and Vancouver. Its capital is Ottawa, and other urban areas include Calgary, Edmonton, Quebec City, Winnipeg. Various aboriginal peoples had inhabited what is now Canada for thousands of years prior to European colonization. Pursuant to the British North America Act, on July 1,1867, the colonies of Canada, New Brunswick and this began an accretion of provinces and territories to the mostly self-governing Dominion to the present ten provinces and three territories forming modern Canada. With the Constitution Act 1982, Canada took over authority, removing the last remaining ties of legal dependence on the Parliament of the United Kingdom. Canada is a parliamentary democracy and a constitutional monarchy, with Queen Elizabeth II being the head of state. The country is officially bilingual at the federal level and it is one of the worlds most ethnically diverse and multicultural nations, the product of large-scale immigration from many other countries. Its advanced economy is the eleventh largest in the world, relying chiefly upon its abundant natural resources, Canadas long and complex relationship with the United States has had a significant impact on its economy and culture. Canada is a country and has the tenth highest nominal per capita income globally as well as the ninth highest ranking in the Human Development Index. It ranks among the highest in international measurements of government transparency, civil liberties, quality of life, economic freedom, Canada is an influential nation in the world, primarily due to its inclusive values, years of prosperity and stability, stable economy, and efficient military. While a variety of theories have been postulated for the origins of Canada. In 1535, indigenous inhabitants of the present-day Quebec City region used the word to direct French explorer Jacques Cartier to the village of Stadacona, from the 16th to the early 18th century Canada referred to the part of New France that lay along the St. Lawrence River. In 1791, the area became two British colonies called Upper Canada and Lower Canada collectively named The Canadas, until their union as the British Province of Canada in 1841. Upon Confederation in 1867, Canada was adopted as the name for the new country at the London Conference. The transition away from the use of Dominion was formally reflected in 1982 with the passage of the Canada Act, later that year, the name of national holiday was changed from Dominion Day to Canada Day
21.
Tape measure
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A tape measure or measuring tape is a flexible ruler. It consists of a ribbon of cloth, plastic, fibre glass and it is a common measuring tool. Its design allows for a measure of length to be easily carried in pocket or toolkit. Today it is ubiquitous, even appearing in miniature form as a keychain fob, Surveyors use tape measures in lengths of over 100 m. Tape measures that were intended for use in tailoring or dressmaking were made from cloth or plastic. These types of tape measures were mainly used for the measuring of the humans waist line. Today, measuring tapes made for sewing are made of fiberglass, measuring tapes designed for carpentry or construction often use a stiff, curved metallic ribbon that can remain stiff and straight when extended, but retracts into a coil for convenient storage. This type of measure will have a floating tang or hook on the end to aid measuring. The tang is connected to the tape with loose rivets through oval holes, a tape measure of 25 or even 100 feet can wind into a relatively small container. The self-marking tape measure allows the user an accurate one hand measure, the first record of a people using a measuring device was by the Romans using marked strips of leather, but this was more like a regular ruler than a tape measure. On July 14,1868, a patent was filed by one Alvin J. Fellows of New Haven, Fellows rule, although crude and flimsy, was the first attempt to make a spring tape measure. On 3 January 1922, Hiram A. Farrand received the patent he filed in 1919 for his tape measure. Sometime between 1922 and December 1926, Farrand experimented with the help of The Brown Company in Berlin and it is there Hiram and William Wentworth Brown began mass-producing the tape measure. Their product was sold to Stanley Works. The basic design on all modern spring tape measures are built can trace its origins back to an 1868 patent by a New Haven. According to the text of his patent, Fellows tape measure was an improvement on other versions previously designed, the spring tape measure has existed since Fellows patent in 1868, but its usage did not become very popular due to the difficulty in communication from one town to another. In the early 1900s, carpenters began slowly adopting H. A. Farrands design as the one commonly used. With the mass production of the circuit the tape measure has also entered into the digital age with the digital tape measure. Some incorporate a digital screen to give measurement readouts in multiple formats, an early patent for this type of measure was published in 1977
22.
Brass
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Brass is a metal alloy made of copper and zinc, the proportions of zinc and copper can be varied to create a range of brasses with varying properties. It is an alloy, atoms of the two constituents may replace each other within the same crystal structure. By comparison, bronze is principally an alloy of copper and tin, however, bronze and brass may also include small proportions of a range of other elements including arsenic, phosphorus, aluminium, manganese, and silicon. The term is applied to a variety of brasses. Modern practice in museums and archaeology increasingly avoids both terms for objects in favour of the all-embracing copper alloy. It is also used in zippers, Brass is often used in situations in which it is important that sparks not be struck, such as in fittings and tools used near flammable or explosive materials. Brass has higher malleability than bronze or zinc, the relatively low melting point of brass and its flow characteristics make it a relatively easy material to cast. By varying the proportions of copper and zinc, the properties of the brass can be changed, allowing hard, the density of brass is 8.4 to 8.73 grams per cubic centimetre. Today, almost 90% of all alloys are recycled. Because brass is not ferromagnetic, it can be separated from ferrous scrap by passing the scrap near a powerful magnet, Brass scrap is collected and transported to the foundry where it is melted and recast into billets. Billets are heated and extruded into the form and size. The general softness of brass means that it can often be machined without the use of cutting fluid, aluminium makes brass stronger and more corrosion-resistant. Aluminium also causes a highly beneficial hard layer of oxide to be formed on the surface that is thin, transparent. Tin has an effect and finds its use especially in seawater applications. Combinations of iron, aluminium, silicon and manganese make brass wear and tear resistant, to enhance the machinability of brass, lead is often added in concentrations of around 2%. Since lead has a melting point than the other constituents of the brass. The pattern the globules form on the surface of the brass increases the available surface area which in turn affects the degree of leaching. In addition, cutting operations can smear the lead globules over the surface and these effects can lead to significant lead leaching from brasses of comparatively low lead content
23.
Copper
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Copper is a chemical element with symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with high thermal and electrical conductivity. A freshly exposed surface of copper has a reddish-orange color. Copper is one of the few metals that occur in nature in directly usable metallic form as opposed to needing extraction from an ore and this led to very early human use, from c.8000 BC. Copper used in buildings, usually for roofing, oxidizes to form a green verdigris, Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as agents, fungicides, and wood preservatives. Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the hemoglobin in fish. In humans, copper is found mainly in the liver, muscle, the adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight. The filled d-shells in these elements contribute little to interatomic interactions, unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper, at the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is supplied in a fine-grained polycrystalline form. The softness of copper partly explains its high conductivity and high thermal conductivity. The maximum permissible current density of copper in open air is approximately 3. 1×106 A/m2 of cross-sectional area, Copper is one of a few metallic elements with a natural color other than gray or silver. Pure copper is orange-red and acquires a reddish tarnish when exposed to air, as with other metals, if copper is put in contact with another metal, galvanic corrosion will occur. A green layer of verdigris can often be seen on old structures, such as the roofing of many older buildings. Copper tarnishes when exposed to sulfur compounds, with which it reacts to form various copper sulfides. There are 29 isotopes of copper, 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper, both have a spin of 3⁄2
24.
Steel
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Steel is an alloy of iron and other elements, primarily carbon, that is widely used in construction and other applications because of its high tensile strength and low cost. Steels base metal is iron, which is able to take on two forms, body centered cubic and face centered cubic, depending on its temperature. It is the interaction of those allotropes with the elements, primarily carbon. In the body-centred cubic arrangement, there is an atom in the centre of each cube. Carbon, other elements, and inclusions within iron act as hardening agents that prevent the movement of dislocations that otherwise occur in the lattices of iron atoms. The carbon in steel alloys may contribute up to 2. 1% of its weight. Steels strength compared to pure iron is possible at the expense of irons ductility. With the invention of the Bessemer process in the mid-19th century and this was followed by Siemens-Martin process and then Gilchrist-Thomas process that refined the quality of steel. With their introductions, mild steel replaced wrought iron, further refinements in the process, such as basic oxygen steelmaking, largely replaced earlier methods by further lowering the cost of production and increasing the quality of the product. Today, steel is one of the most common materials in the world and it is a major component in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons. Modern steel is generally identified by various grades defined by assorted standards organizations, the noun steel originates from the Proto-Germanic adjective stakhlijan, which is related to stakhla. The carbon content of steel is between 0. 002% and 2. 1% by weight for plain iron–carbon alloys and these values vary depending on alloying elements such as manganese, chromium, nickel, iron, tungsten, carbon and so on. Basically, steel is an alloy that does not undergo eutectic reaction. In contrast, cast iron does undergo eutectic reaction, too little carbon content leaves iron quite soft, ductile, and weak. Carbon contents higher than those of steel make an alloy, commonly called pig iron, while iron alloyed with carbon is called carbon steel, alloy steel is steel to which other alloying elements have been intentionally added to modify the characteristics of steel. Common alloying elements include, manganese, nickel, chromium, molybdenum, boron, titanium, vanadium, tungsten, cobalt, and niobium. Additional elements are important in steel, phosphorus, sulfur, silicon, and traces of oxygen, nitrogen, and copper. Alloys with a higher than 2. 1% carbon content, depending on other element content, cast iron is not malleable even when hot, but it can be formed by casting as it has a lower melting point than steel and good castability properties
25.
Nickel
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Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a golden tinge. Nickel belongs to the metals and is hard and ductile. Meteoric nickel is found in combination with iron, a reflection of the origin of elements as major end products of supernova nucleosynthesis. An iron–nickel mixture is thought to compose Earths inner core, use of nickel has been traced as far back as 3500 BCE. Nickel was first isolated and classified as an element in 1751 by Axel Fredrik Cronstedt. The elements name comes from a mischievous sprite of German miner mythology, Nickel, an economically important source of nickel is the iron ore limonite, which often contains 1–2% nickel. Nickels other important ore minerals include garnierite, and pentlandite, major production sites include the Sudbury region in Canada, New Caledonia in the Pacific, and Norilsk in Russia. Nickel is slowly oxidized by air at room temperature and is considered corrosion-resistant, historically, it has been used for plating iron and brass, coating chemistry equipment, and manufacturing certain alloys that retain a high silvery polish, such as German silver. About 6% of world production is still used for corrosion-resistant pure-nickel plating. Nickel-plated objects sometimes provoke nickel allergy, Nickel has been widely used in coins, though its rising price has led to some replacement with cheaper metals in recent years. Nickel is one of four elements that are ferromagnetic around room temperature, alnico permanent magnets based partly on nickel are of intermediate strength between iron-based permanent magnets and rare-earth magnets. The metal is valuable in modern times chiefly in alloys, about 60% of world production is used in nickel-steels, other common alloys and some new superalloys comprise most of the remainder of world nickel use, with chemical uses for nickel compounds consuming less than 3% of production. As a compound, nickel has a number of chemical manufacturing uses. Nickel is a nutrient for some microorganisms and plants that have enzymes with nickel as an active site. Nickel is a metal with a slight golden tinge that takes a high polish. It is one of four elements that are magnetic at or near room temperature. Its Curie temperature is 355 °C, meaning that bulk nickel is non-magnetic above this temperature, the unit cell of nickel is a face-centered cube with the lattice parameter of 0.352 nm, giving an atomic radius of 0.124 nm
26.
International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
27.
Metalworking
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Metalworking is the process of working with metals to create individual parts, assemblies, or large-scale structures. The term covers a range of work from large ships and bridges to precise engine parts. It therefore includes a wide range of skills, processes. Metalworking is a science, art, hobby, industry and trade and its historical roots span cultures, civilizations, and millennia. Metalworking has evolved from the discovery of smelting various ores, producing malleable and ductile metal useful for tools, modern metalworking processes, though diverse and specialized, can be categorized as forming, cutting, or joining processes. Todays machine shop includes a number of machine tools capable of creating a precise, the oldest archaeological evidence of copper mining and working was the discovery of a copper pendant in northern Iraq from 8,700 BCE. The earliest substantiated and dated evidence of metalworking in the Americas was the processing of copper in Wisconsin, Copper was hammered until brittle then heated so it could be worked some more. This technology is dated to about 4000-5000 BCE, the oldest gold artifacts in the world come from the Bulgarian Varna Necropolis and date from 4450 BCE. Not all metal required fire to obtain it or work it, isaac Asimov speculated that gold was the first metal. His reasoning is that by its chemistry it is found in nature as nuggets of pure gold, in other words, gold, as rare as it is, is sometimes found in nature as the metal that it is. There are a few metals that sometimes occur natively. Almost all other metals are found in ores, a mineral-bearing rock, another feature of gold is that it is workable as it is found, meaning that no technology beyond a stone hammer and anvil to work the metal is needed. This is a result of properties of malleability and ductility. The earliest tools were stone, bone, wood, and sinew, at some unknown point the connection between heat and the liberation of metals from rock became clear, rocks rich in copper, tin, and lead came into demand. These ores were mined wherever they were recognized, remnants of such ancient mines have been found all over Southwestern Asia. Metalworking was being carried out by the South Asian inhabitants of Mehrgarh between 7000–3300 BCE, the end of the beginning of metalworking occurs sometime around 6000 BCE when copper smelting became common in Southwestern Asia. Ancient civilisations knew of seven metals. Here they are arranged in order of their potential, Iron +0.44 V
28.
Bandsaw
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A bandsaw is a saw with a long sharp blade consisting of a continuous band of toothed metal stretched between two or more wheels to cut material. They are used principally in woodworking, metalworking, and lumbering, advantages include uniform cutting action as a result of an evenly distributed tooth load, and the ability to cut irregular or curved shapes like a jigsaw. The minimum radius of a curve is determined by the width of the band, most bandsaws have two wheels rotating in the same plane, one of which is powered, although some may have three or four to distribute the load. The blade itself can come in a variety of size and tooth pitch which enables the machine to be versatile and able to cut a wide variety of materials including wood, metal. Almost all bandsaws today are powered by an electric motor, line shaft versions were once common but are now antiques. Constant flexing of the blade over the wheels caused either the material or the joint welding it into a loop to fail, nearly 40 years passed before Frenchwoman Anne Paulin Crepin devised a welding technique overcoming this hurdle. She applied for a patent in 1846, and soon sold the right to employ it to manufacturer A. Perin & Company of Paris. Combining this method with new alloys and advanced tempering techniques allowed Perin to create the first modern band saw blade. The first American band saw patent was granted to Benjamin Barker of Ellsworth, Maine, the first factory produced and commercially available band saw in the U. S. was by a design of Paul Prybil. Power hacksaws were once common in the industries, but bandsaws. Many workshops in residential garages or basements and in light industry contain small or medium-sized bandsaws that can cut wood, metal, often a general-purpose blade is left in place, although blades optimized for wood or metal can be switched out when volume of use warrants. Most residential and commercial bandsaws are of the vertical type mounted on a bench or a cabinet stand, Portable power tool versions, including cordless models, are also common in recent decades, allowing building contractors to bring them along on the truck to the jobsite. Saws for cutting meat are typically of all steel construction with easy to clean features. The blades either have fine teeth with heat treated tips, or have plain or scalloped knife edges, bandsaws dedicated to industrial metal-cutting use, such as for structural steel in fabrication shops and for bar stock in machine shops, are available in vertical and horizontal designs. Typical band speeds range from 40 feet per minute to 5,000 feet per minute, although specialized bandsaws are built for friction cutting of hard metals, metal-cutting bandsaws are usually equipped with brushes or brushwheels to prevent chips from becoming stuck in between the blades teeth. Systems which cool the blade with cutting fluid are also common equipment on metal-cutting bandsaws, the coolant washes away swarf and keeps the blade cool and lubricated. Horizontal bandsaws hold the workpiece stationary while the blade swings down through the cut and this configuration is used to cut long materials such as pipe or bar stock to length. Thus it is an important part of the facilities in most machine shops, the horizontal design is not useful for cutting curves or complicated shapes
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Cold saw
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This is contrast to an abrasive saw, which abrades the metal and generates a great deal of heat absorbed by the material being cut and saw blade. As metals expand when heated, abrasive cutting causes both the material being cut and blade to expand, resulting in increased effort to produce a cut and this produces more heat through friction, resulting in increased blade wear and greater energy consumption. Cold saws use either a high speed steel or tungsten carbide-tipped. They are equipped with a motor and a gear reduction unit to reduce the saw blades rotational speed while maintaining constant torque. This allows the HSS saw blade to feed at a constant rate with a high chip load per tooth. Cold saws are capable of machining most ferrous and non-ferrous alloys, additional advantages include minimal burr production, fewer sparks, less discoloration and no dust. Saws designed to employ a flood coolant system to keep saw blade teeth cooled and lubricated may reduce sparks, cold saw blades are circular metal cutting saw blades categorized into two types, solid HSS or tungsten carbide-tipped. Both types of blades are resharpenable and may be used many times before being discarded. Cold saw blades are used to cut metal using a relatively slow speed, usually less than 5000 surface feet per minute. These blades are driven by a high motor and high-torque gear reduction unit or an AC vector drive. During the cutting process, the metal is released in an action by the teeth as the blade turns. They are called cold saw blades because they transfer all the energy and this enables the blade and the work material to remain cold. The first type of cold saw blade, solid HSS, may be made from either M2 tool steel or M35 tool steel, solid HSS saw blades are heat treated and hardened to 64/65 HRC for ferrous cutting applications and 58/60 HRC for non-ferrous cutting applications. This high hardness gives the cutting edges of the teeth a high resistance to heat, however, this increased hardness also makes the blades brittle and not very resistant to shock. In order to produce a high quality HSS cold saw blade, you must start with very flat, the blades must be press quenched after hardening to prevent them from being warped. HSS saw blades are typically hollow ground for clearance during the cutting process, the term HSS doesnt necessarily mean what it implies. These blades are usually never run at speeds higher than 350 SFM. Solid HSS cold saw blades may be used for cutting many different shapes and types of metal including, tubes, extrusions, structural sections, billets, bars, ingots, castings, forgings etc
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Laser cutting
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Laser cutting works by directing the output of a high-power laser most commonly through optics. The laser optics and CNC are used to direct the material or the laser beam generated, a typical commercial laser for cutting materials would involve a motion control system to follow a CNC or G-code of the pattern to be cut onto the material. The focused laser beam is directed at the material, which then melts, burns, vaporizes away, or is blown away by a jet of gas. Industrial laser cutters are used to cut flat-sheet material as well as structural, in 1965, the first production laser cutting machine was used to drill holes in diamond dies. This machine was made by the Western Electric Engineering Research Center, in 1967, the British pioneered laser-assisted oxygen jet cutting for metals. In the early 1970s, this technology was put into production to cut titanium for aerospace applications. At the same time CO2 lasers were adapted to cut non-metals, such as textiles, because, at the time, generation of the laser beam involves stimulating a lasing material by electrical discharges or lamps within a closed container. As the lasing material is stimulated, the beam is reflected internally by means of a partial mirror, mirrors or fiber optics are typically used to direct the coherent light to a lens, which focuses the light at the work zone. The narrowest part of the beam is generally less than 0.0125 inches. Depending upon material thickness, kerf widths as small as 0.004 inches are possible, in order to be able to start cutting from somewhere other than the edge, a pierce is done before every cut. Piercing usually involves a high-power pulsed laser beam which slowly makes a hole in the material, taking around 5–15 seconds for 0. 5-inch-thick stainless steel, for example. The parallel rays of coherent light from the laser source often fall in the range between 0. 06–0.08 inches in diameter. This beam is focused and intensified by a lens or a mirror to a very small spot of about 0.001 inches to create a very intense laser beam. In order to achieve the smoothest possible finish during contour cutting, for sheet metal cutting, the focal length is usually 1. 5–3 inches. Advantages of laser cutting over mechanical cutting include easier workholding and reduced contamination of workpiece, precision may be better, since the laser beam does not wear during the process. There is also a chance of warping the material that is being cut. Some materials are very difficult or impossible to cut by more traditional means. There are three types of lasers used in laser cutting
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Miter saw
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A miter saw is a saw used to make accurate crosscuts and miters in a workpiece. A power miter saw, also known as a saw, is a power tool used to make a quick. Common uses include framing operations and the cutting of molding and trim, most miter saws are relatively small and portable, with common blade sizes ranging from eight to twelve inches. The miter saw makes cuts by pulling a spinning saw blade down onto a workpiece in a short. The workpiece is held against a fence, which provides a precise cutting angle between the plane of the blade and the plane of the longest workpiece edge. In standard position, this angle is fixed at 90°, a primary distinguishing feature of the miter saw is the miter index that allows the angle of the blade to be changed relative to the fence. While most miter saws enable precise one-degree incremental changes to the miter index, there are several types of power miter saws, Miter saws are dedicated cross cut saws, long rip cuts are not possible. A laser guide provides a visual indication of where the cut will be positioned on the workpiece in the current configuration. Some models provide a reference line for one side of the kerf. A blade guard is a cover for the teeth of the cutting blade, most modern miter saws have self-retracting blade guards, which automatically retract when the saw is lowered onto a workpiece and re-cover the blade when the saw is raised. It is very dangerous to use the saw if these guards are removed or damaged, a dust bag connects directly to the saw, and helps to collect sawdust away from the workpiece during cutting. Optionally, many manufacturers sell adapters to connect an industrial vacuum cleaner in lieu of a bag to capture more of the dust, dust removal with these saws is notoriously poor. A safety clamp helps to lock a workpiece into position prior to making a cut and this is an especially important feature when cutting smaller workpieces. The miter table is typically less than 24 in diameter, typically, the work will need to be supported on the far end to stabilize the piece while cutting. Miter saws are inherently low hazard as the workpiece is held stationary against a fence while the saw head moves, making kick back almost impossible, also the saw head is usually drawn back, then lowered and fed forward through the material so that binding is unlikely. Sliding compound miter saws are relatively portable, easy to set up, because they cut from above it is not necessary to adjust blade depth for different thicknesses of work piece and, like any bench machine, repeat cuts are very easy. Most saws have an adjustable scale plate for table swiveling with positive stops at commonly used angles, also, there are usually adjustable stops at 90 and 45 degrees for head tilting allowing easy and very accurate adjustment of the saw. Table swiveling in both directions is universal but most saws allow head tilting only in one direction, although some saws allow head tilting in both directions
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Plasma cutting
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Plasma cutting is a process that cuts through electrically conductive materials by means of an accelerated jet of hot plasma. Typical materials cut with a plasma torch include steel, Stainless steel, aluminum, brass and copper, Plasma cutting is often used in fabrication shops, automotive repair and restoration, industrial construction, and salvage and scrapping operations. Due to the speed and precision cuts combined with low cost. This is accomplished by a gas which is blown through a focused nozzle at high speed toward the work piece. An electrical arc is formed within the gas, between an electrode near or integrated into the gas nozzle and the work piece itself. The electrical arc ionizes some of the gas, thereby creating a conductive channel of plasma. As electricity from the cutter torch travels down this plasma it delivers sufficient heat to melt through the work piece. At the same time, much of the high velocity plasma and compressed gas blow the hot molten metal away, Plasma cutting is an effective means of cutting thin and thick materials alike. Hand-held torches can cut up to 38 mm thick steel plate. Since plasma cutters produce a hot and very localized cone to cut with. Plasma cutting grew out of plasma welding in the 1960s, and emerged as a productive way to cut sheet metal. It had the advantages over traditional metal against metal cutting of producing no metal chips, giving accurate cuts, early plasma cutters were large, somewhat slow and expensive and, therefore, tended to be dedicated to repeating cutting patterns in a mass production mode. These CNC plasma cutting machines were, however, generally limited to cutting patterns and parts in flat sheets of steel, proper eye protection and face shields are needed to prevent eye damage called arc eye as well as damage from debris. It is recommended to use green lens shade #5, OSHA recommends a shade 8 for arc current less than 300, but notes that These values apply where the actual arc is clearly seen. Experience has shown that lighter filters may be used when the arc is hidden by the workpiece, lincoln Electric, a manufacturer of plasma cutting equipment, says, Typically a darkness shade of #7 to #9 is acceptable. Plasma cutters use a number of methods to start the arc, in some units, the arc is created by putting the torch in contact with the work piece. Some cutters use a voltage, high frequency circuit to start the arc. This method has a number of disadvantages, including risk of electrocution, difficulty of repair, spark gap maintenance, Plasma cutters working near sensitive electronics, such as CNC hardware or computers, start the pilot arc by other means
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Water jet cutter
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Waterjet cutting is often used during fabrication of machine parts. It is the method when the materials being cut are sensitive to the high temperatures generated by other methods. Waterjet cutting is used in industries, including mining and aerospace, for cutting, shaping. These early applications were at a low pressure and restricted to soft materials like paper, Waterjet technology evolved in the post-war era as researchers around the world searched for new methods of efficient cutting systems. In 1958, Billie Schwacha of North American Aviation developed a system using ultra-high-pressure liquid to cut hard materials and this system used a 100,000 psi pump to deliver a hypersonic liquid jet that could cut high strength alloys such as PH15-7-MO stainless steel. Used as a honeycomb laminate on the Mach 3 North American XB-70 Valkyrie, while not effective for the XB-70 project, the concept was valid and further research continued to evolve waterjet cutting. In 1962, Philip Rice of Union Carbide explored using a pulsing waterjet at up to 50,000 psi to cut metals, stone, research by S. J. Leach and G. L.002 inches that operated at pressures up to 70,000 psi. High-pressure vessels and pumps became affordable and reliable with the advent of steam power, by the mid-1800s, steam locomotives were common and the first efficient steam-driven fire engine was operational. By the turn of the century, high-pressure reliability improved, with research leading to a sixfold increase in boiler pressure. Most high-pressure pumps at this time, though, operated around 500–800 psi, high-pressure systems were further shaped by the aviation, automotive, and oil industries. Aircraft manufacturers such as Boeing developed seals for hydraulically boosted control systems in the 1940s, higher pressures in hydraulic systems in the oil industry also led to the development of advanced seals and packing to prevent leaks. These advances in technology, plus the rise of plastics in the post-war years. The invention of Marlex by Robert Banks and John Paul Hogan of the Phillips Petroleum company required a catalyst to be injected into the polyethylene, mcCartney Manufacturing Company in Baxter Springs, Kansas, began manufacturing these high-pressure pumps in 1960 for the polyethylene industry. Flow Industries then combined the high-pressure pump research with their waterjet nozzle research, while cutting with water is possible for soft materials, the addition of an abrasive turned the waterjet into a modern machining tool for all materials. This began in 1935 when the idea of adding an abrasive to the stream was developed by Elmo Smith for the liquid abrasive blasting. The March 1984 issue of the Mechanical Engineering magazine showed more details and materials cut with AWJ such as titanium, aluminum, glass, dr. Mohamed Hashish, was awarded a patent on forming AWJ in 1987. Current work on AWJ nozzles is on micro abrasive waterjet so cutting with jets smaller than 0.015 inches in diameter can be commercialized. By January,1985, that system was being run 24 hours a day producing titanium parts for the B-1B largely at Rockwells North American Aviation facility in Newark, as waterjet cutting moved into traditional manufacturing shops, controlling the cutter reliably and accurately was essential
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Broaching (metalworking)
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Broaching is a machining process that uses a toothed tool, called a broach, to remove material. There are two types of broaching, linear and rotary. In linear broaching, which is the common process, the broach is run linearly against a surface of the workpiece to effect the cut. Linear broaches are used in a machine, which is also sometimes shortened to broach. In rotary broaching, the broach is rotated and pressed into the workpiece to cut an axis symmetric shape, a rotary broach is used in a lathe or screw machine. In both processes the cut is performed in one pass of the broach, which makes it very efficient, Broaching is used when precision machining is required, especially for odd shapes. Commonly machined surfaces include circular and non-circular holes, splines, keyways, typical workpieces include small to medium-sized castings, forgings, screw machine parts, and stampings. Even though broaches can be expensive, broaching is usually favored over other processes used for high-quantity production runs. Broaches are shaped similar to a saw, except the height of the teeth increases over the length of the tool, moreover, the broach contains three distinct sections, one for roughing, another for semi-finishing, and the final one for finishing. Broaching is a machining process because it has the feed built into the tool. The profile of the surface is always the inverse of the profile of the broach. The rise per tooth, also known as the step or feed per tooth, determines the amount of material removed, the broach can be moved relative to the workpiece or vice versa. Because all of the features are built into the broach no complex motion or skilled labor is required to use it. A broach is effectively a collection of single-point cutting tools arrayed in sequence, cutting one after the other, the process depends on the type of broaching being performed. Surface broaching is very simple as either the workpiece is moved against a stationary surface broach, the process begins by clamping the workpiece into a special holding fixture, called a workholder, which mounts in the broaching machine. The broaching machine elevator, which is the part of the machine moves the broach above the workholder. Once through, the broaching machines puller, essentially a hook, the elevator then releases the top of the pilot and the puller pulls the broach through the workpiece completely. The workpiece is then removed from the machine and the broach is raised back up to reengage with the elevator, the broach usually only moves linearly, but sometimes it is also rotated to create a spiral spline or gun-barrel rifling
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Burr (cutter)
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Burrs are small cutting tools used in die grinders, rotary tools, or dental drills. The name may be considered appropriate when their head is compared to a bur or their teeth are compared to a metal burr. Burrs are an analog to files that cut linearly. They are also in many ways comparable to endmills and to router bits, however, there is substantial overlap in the use and toolpath control of these various classes of cutters, and in the outcomes accomplished with them. For example, endmills can be used in routers, and burrs can be used like endmills in milling by CNC or manual machine tools, in fact, burrs are often used in CNC machining centers for removing burrs after a machining process. To maintain the surface speed and cutting conditions, burrs are rotated at high speed. The cutters shown in the image are made from tungsten carbide, hard metal or ceramic workpieces cannot flex beyond the cutting edges, so the tools remove material from them. This characteristic makes them suitable for dentistry, as the tool will grind the hard enamel of teeth, yet leaves soft mouth tissues unharmed if the tool should erroneously touch them
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Chisel
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The handle and blade of some types of chisel are made of metal or of wood with a sharp edge in it. Chiselling use involves forcing the blade into some material to cut it, the driving force may be applied by pushing by hand, or by using a mallet or hammer. In industrial use, a ram or falling weight drives a chisel into the material. A gouge, one type of chisel, serves - particularly in woodworking, woodturning, gouges most frequently produce concave surfaces. A gouge typically has a U-shaped cross-section, chisel comes from the Old French cisel, modern ciseau, Late Latin cisellum, a cutting tool, from caedere, to cut. Chisels have a variety of uses. Many types of chisel have been devised, each suited to its intended use. Different types of chisel may be constructed differently, in terms of blade width or length, as well as shape. They may have a wooden or plastic handle attached using a tang or socket, woodworking chisels range from small hand tools for tiny details, to large chisels used to remove big sections of wood, in roughing out the shape of a pattern or design. Typically, in woodcarving, one starts with a larger tool, one of the largest types of chisel is the slick, used in timber frame construction and wooden shipbuilding. There are many types of woodworking chisels used for specific purposes, such as, Butt chisel, short chisel with beveled sides and straight edge for creating joints. Carving chisels, used for designs and sculpting, cutting edges are many, such as gouge, skew, parting, straight, paring. Corner chisel, resembles a punch and has an L-shaped cutting edge, cleans out square holes, mortises and corners with 90 degree angles. Bevel edge chisel, can get into acute angles with its bevelled edges, flooring chisel, cuts and lifts flooring materials for removal and repair, ideal for tongue-and-groove flooring. Framing chisel, usually used with mallet, similar to a chisel, except it has a longer. Slick, a large chisel driven by pressure, never struck. Mortise chisel, thick, rigid blade with cutting edge and deep, slightly tapered sides to make mortises. Paring chisel, has a long blade ideal for cleaning grooves, skew chisel, has a 60 degree cutting angle and is used for trimming and finishing
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Counterbore
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A counterbore is a cylindrical flat-bottomed hole that enlarges another coaxial hole, or the tool used to create that feature. A counterbore hole is used when a fastener, such as a socket head cap screw, is required to sit flush with or below the level of a workpieces surface. Whereas a counterbore is an enlargement of a smaller coaxial hole. A spotface often takes the form of a very shallow counterbore, as mentioned above, the cutters that produce counterbores are often also called counterbores, sometimes, to avoid ambiguity, the term counterbore cutter is used instead. A counterbore hole is used when the head of a fastener. For a spotface, material is removed from a surface to make it flat and smooth, spotfacing is usually required on workpieces that are forged or cast. A tool referred to as a counterbore is typically used to cut the spotface, only enough material is removed to make the surface flat. A counterbore is also used to create a surface for a fastener head on a non-perpendicular surface. If this is not feasible then a self-aligning nut may be required, by comparison, a countersink makes a conical hole and is used to seat a flathead screw. Standards exist for the sizes of counterbores, especially for fastener head seating areas and these standards can vary between corporations and between standards organizations. This is in contrast to the ASME Y14. 5-2009 definition of a spotface, counterbores are made with standard dimensions for a certain size of screw or are produced in sizes that are not related to any particular screw size. Counterbores matched to specific screw sizes generally have integral pilots that fit the hole diameter associated with a particular screw size. Counterbores that are not related to a specific screw size are designed to accept a removable pilot, the pilot matters little when running the cutter in a milling setup where rigidity is assured and hole center location is already achieved via X-Y positioning. The uppermost counterbore tools shown in the image are the same device, the smaller top item is an insert, the middle shows another three-fluted counterbore insert, assembled in the holder. The shank of this holder is a Morse taper, although there are other machine tapers that are used in the industry, the lower counterbore is designed to fit into a drill chuck, and being smaller, is economical to make as one piece. Countersink Degarmo, E. Paul, Black, J T. Kohser, materials and Processes in Manufacturing, Wiley, ISBN 0-471-65653-4
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Countersink
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A countersink is a conical hole cut into a manufactured object, or the cutter used to cut such a hole. A common use is to allow the head of a bolt or screw. A countersink may also be used to remove the burr left from a drilling or tapping operation thereby improving the finish of the product, the basic geometry of a countersink inherently can be applied to the plunging applications described above and also to other milling applications. Therefore, countersinks overlap in form, function, and sometimes name with chamfering endmills, regardless of the name given to the cutter, the surface being generated may be a conical chamfer or a beveled corner for the intersection of two planes. A countersink may be used in tools, such as drills, drill presses, milling machines. A Dan Martin Style zero flute countersink is a tool with a cutting edge provided by a hole that goes through the side of the cone. The intersection of the hole and cone form the edge on the tool. The cone is not truly symmetrical as it is essential that the cone retreats away from the edge as the tool rotates providing clearance. If this does not occur the cutting edge will lack clearance and this clearance is referred to as cutting relief. The fluted countersink cutter is used to provide a heavy chamfer in the entrance to a drilled hole and this may be required to allow the correct seating for a countersunk-head screw or to provide the lead in for a second machining operation such as tapping. Countersink cutters are manufactured with six common angles, which are 60°, 82°, 90°, 100°, 110°, or 120°, with the two most common of those being 82° and 90°. Countersunk-head screws that follow the Unified Thread Standard very often have an 82° angle, throughout the aerospace industry, countersunk fasteners typically have an angle of 100°. A back countersink, also known as an inserted countersink, is a two piece countersink used on tough to reach areas. One component is a rod that is inserted into the hole in the workpieces, the other component is the cutter. This is comparable to types of back- machining, such as back-spotfacing, back-boring, back-counterboring, back-milling. The common theme is accomplishing machining operations on the far side of the workpiece from the spindle face and this reduces setup time and frustration in several ways. It can often be difficult to avoid chatter when cutting with countersink cutters, as usual in machining, the shorter and more rigid the setup, the better. Better-quality fluted countersink cutters sometimes have the flutes at an irregular pitching and this variation in pitching reduces the chance of the cutting edges setting up a harmonic action and leaving an undulated surface
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End mill
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An end mill is a type of milling cutter, a cutting tool used in industrial milling applications. It is distinguished from the bit in its application, geometry. While a drill bit can only cut in the axial direction, end mills are used in milling applications such as profile milling, tracer milling, face milling, and plunging. Each category may be divided by specific application and special geometry. It is becoming common for traditional solid end mills to be replaced by more cost-effective inserted cutting tools. End mills are sold in imperial and metric shank and cutting diameters. In the USA, metric is readily available, but it is used in some machine shops and not others, in Canada, due to the countrys proximity to the US. In Asia and Europe, metric diameters are standard, a variety of grooves, slots, and pockets in the work-piece may be produced from a variety of tool bits. Common tool bit types are, square end cutters, ball end cutters, t-slot cutters, square end cutters can mill square slots, pockets, and edges. Ball end cutters mill radiused slots or fillets, t-slot cutters mill exactly that, T-shaped slots. Shell end cutters are used for flat surfaces and for angle cuts. There are variations of these types as well. There are four angles of each cutting tool, end cutting edge angle, axial relief angle, radial relief angle. Depending on the material being milled, and what task should be performed, different tool types and geometry may be used. For instance, when milling a material like aluminium, it may be advantageous to use a tool with very deep, polished flutes, when machining a tough material such as stainless steel, however, shallow flutes and a squared-off cutting edge will optimize material removal and tool life. A wide variety of materials are used to produce the cutting tools, carbide inserts are the most common because they are good for high production milling. High speed steel is used when a special tool shape is needed. Ceramics inserts are typically used in high speed machining with high production, Diamond inserts are typically used on products that require tight tolerances, typically consisting of high surface qualities
40.
File (tool)
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A file is a tool used to remove fine amounts of material from a workpiece. It is common in woodworking, metalworking, and other similar trade, most are hand tools, made of a case hardened steel bar of rectangular, square, triangular, or round cross-section, with one or more surfaces cut with sharp, generally parallel teeth. A narrow, pointed tang is common at one end, to which a handle may be fitted, a rasp is a form of file with distinct, individually cut teeth used for coarsely removing large amounts of material. Files have also developed with abrasive surfaces, such as natural or synthetic diamond grains or silicon carbide, allowing removal of material that would dull or resist metal. Relatedly, lapping is also ancient, with wood and beach sand offering a natural pair of lap. The Disston authors state, To abrade, or file, ancient man used sand, grit, coral, bone, fish skin, the Bronze Age and the Iron Age had various kinds of files and rasps. Archaeologists have discovered rasps made from bronze in Egypt, dating back to the years 1200–1000 BC, archaeologists have also discovered rasps made of iron used by the Assyrians, dating back to the 7th Century BC. During the Middle Ages files were already advanced, thanks to the extensive talents of blacksmiths. By the 11th century, there already existed hardened files that would seem quite modern even to todays eyes. For example, in the 13th century, ornamental iron work at Paris was done skillfully with the aid of files, but the process was a secret known only to a master craftsman. The Disston authors state, It was not until the fourteenth century, however, that those who practiced art in ironwork began to use tools, besides heat. This statement could mislead in the sense that stoning and lapping have never been rare activities among humans, but by the late Middle Ages, however, the transition was extensive. The Disston authors mention Nuremberg, Sheffield, and Remscheid as leading centers of production for files as well as tools in general, the activity in Remscheid reflects the metalworking spirit of the Rhine-Ruhr region in general rather than representing a single village of geniuses in isolation. Most files of the period were smithed by hand in a sequence in which the iron was forged, then the teeth were cut with a chisel, among the drawings of Leonardo da Vinci is a sketch of a machine tool for the cutting of files. Prior to the industrialization of machining and the development of parts during the 19th century. Component parts were roughly shaped by forging, casting, and by primitive machining operations and these components were then individually hand-fit for assembly by careful and deliberate filing. The potential precision of fitting is much higher than generally assumed. Locks, clocks, and firearms were manufactured in this way for centuries before the Industrial Revolution, machining in the mid-19th century was heavily dependent on filing, because milling practice was slowly evolving out of its infancy
41.
Hand scraper
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A hand scraper is a single-edged tool used to scrape metal from a surface. This may be required where a surface needs to be trued, corrected for fit to a part, needs to retain oil. Surface plates were made by scraping. Three raw cast surface plates, a scraper and a quantity of bearing blue were all that was required in the way of tools. The scraper in the center of the image is a three corner scraper and is used to deburr holes or the internal surface of bush type bearings. Bushes are typically made from bronze or a white metal, the scraper pictured at the bottom is a curved scraper. It has a curve in its profile and is also suitable for bush bearings. One advantage of scraping is the ability to take the tool to the workpiece, the person that scrapes is called a hand. It is done by using a precision surface such as a surface plate or a straight edge as a standard. The standard is coated with a thin coating of a material such as Prussian blue. The work piece and standard are touched together by gravity alone and these high spots are scraped off and the process repeated until there is an even spread of high spots which total about 60% or more of the surface area. Coarse scraping gives a surface with 5-10 points per square inch while fine scraping yields 24-36 points per square inch. If desired the surface can then be “Frosted”, a surface prepared in this way is superior in overall accuracy to any prepared by machining or grinding operations, although lapping can equal or exceed it over small distances. Grinding and machining stresses the metal thermally and mechanically, scraping and lapping do not, with precision ground surfaces, any oil film applied to the surface will lack the means to adhere to the surface, especially between two mating parts of exceptional finish. The oil film will be swept away leaving nothing but bare metal, carefully scraping the surface will leave the original high quality surface intact, but provide many shallow depressions where the oil film can maintain its depth and surface tension. When scraping is used for this purpose it is more accurately called frosting, spotting or flaking as opposed to fully scraping an accurate surface, typically a scraped surface is scraped to highly accurate flatness and then frosting is applied over it for oil retention. It is claimed to stop the so-called stick-slip phenomenon where a member might move in a jerky fashion rather than moving smoothly, allowing vibration. Such frosting will definitely increase oil retention but will also drastically reduce bearing area, there is no possibility of achieving hydrodynamic bearing performance on normal sliding machine ways. The velocity is far too low, most of the time the ways will run under boundary lubrication conditions while at the highest speeds it might achieve mixed lubrication
42.
Milling cutter
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Milling cutters are cutting tools typically used in milling machines or machining centres to perform milling operations. They remove material by their movement within the machine or directly from the cutters shape, milling cutters come in several shapes and many sizes. There is also a choice of coatings, as well as rake angle, shape, Several standard shapes of milling cutter are used in industry today, which are explained in more detail below. Flutes / teeth, The flutes of the bit are the deep helical grooves running up the cutter. The tooth cuts the material, and chips of material are pulled up the flute by the rotation of the cutter. There is almost always one tooth per flute, but some cutters have two teeth per flute, often, the words flute and tooth are used interchangeably. Milling cutters may have one to many teeth, with 2,3 and 4 being most common. Typically, the teeth a cutter has, the more rapidly it can remove material. So, a 4-tooth cutter can remove material at twice the rate of a 2-tooth cutter, helix angle, The flutes of a milling cutter are almost always helical. If the flutes were straight, the tooth would impact the material at once, causing vibration and reducing accuracy. Setting the flutes at an angle allows the tooth to enter the material gradually, typically, finishing cutters have a higher rake angle to give a better finish. Center cutting, Some milling cutters can drill straight down through the material and this is because the teeth of some cutters do not go all the way to the centre of the end face. However, these cutters can cut downwards at an angle of 45 degrees or so, a roughing cutter may have serrated teeth for breaking the chips of material into smaller pieces. These teeth leave a surface behind. A finishing cutter may have a large number teeth for removing material carefully, however, the large number of flutes leaves little room for efficient swarf removal, so they are less appropriate for removing large amounts of material. Coatings, The right tool coatings can have an influence on the cutting process by increasing cutting speed and tool life. Polycrystalline diamond is a hard coating used on cutters which must withstand high abrasive wear. A PCD coated tool may last up to 100 times longer than an uncoated tool, however the coating cannot be used at temperatures above 600 degrees C, or on ferrous metals
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Reamer
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A reamer is a type of rotary cutting tool used in metalworking. Precision reamers are designed to enlarge the size of a previously formed hole by a small amount, there are also non-precision reamers which are used for more basic enlargement of holes or for removing burrs. The process of enlarging the hole is called reaming, there are many different types of reamer and they may be designed for use as a hand tool or in a machine tool, such as a milling machine or drill press. A typical reamer consists of a set of straight or helical cutting edges along the length of a cylindrical body. Each cutting edge is ground at a angle and with a slight undercut below the cutting edge. Reamers must combine both hardness in the edges, for long life, and toughness, so that the tool does not fail under the normal forces of use. They should only be used to small amounts of material. This ensures a long life for the reamer and a finish to the hole. The spiral may be clockwise or counter-clockwise depending on usage, for example, a tapered hand reamer with a clockwise spiral will tend to self feed as it is used, possibly leading to a wedging action and consequent breakage. A counter-clockwise spiral is therefore preferred even though the reamer is still turned in the clockwise direction, for hand tools, the shank end is usually a square drive, intended for use with the same type of wrench used to turn a tap for the cutting of screw threads. The geometry of a hole drilled in metal by a twist drill may not be accurate enough, the planned difference between the drill diameter and the reamer diameter is called an allowance. The allowance should be <0.2 mm for soft materials, larger allowances can damage the reamer. The drilled hole should not be enlarged by more than 5% of the drilled diameter, drilling followed by reaming generally produces hole geometry and finish that is as close to theoretical perfection as possible. An adjustable hand reamer can cover a range of sizes. They are generally referenced by a letter which equates to a size range, the disposable blades slide along a tapered groove. The act of tightening and loosening the restraining nuts at each end varies the size that may be cut, the absence of any spiral in the flutes restricts them to light usage as they have a tendency to chatter. They are also restricted to usage in unbroken holes, if a hole has an axial split along it, such as a split bush or a clamping hole, each straight tooth will in turn drop into the gap causing the other teeth to retract from their cutting position. This also gives rise to chatter marks and defeats the purpose of using the reamer to size a hole, a straight reamer is used to make only a minor enlargement to a hole
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Shear (sheet metal)
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There are many types of shears used to shear sheet metal. A bench shear, also known as a shear, is a bench mounted shear with a compound mechanism to increase the mechanical advantage. It is usually used for cutting rough shapes out of medium-sized pieces of sheet metal, for the small shear, it mostly designed for a wide field of applications. Light weight and easy efficient operation, yet very sturdy in construction, the cutting blades fitted are carefully and accurately ground to give easy, clean quick cuts, and free of burrs. These special features help the operators save a great deal of their energy, but some shearing machines can cut sheet bar and flat bar up to 10mm. It is electrically welded together to make it a sturdy stable unit capable to withstand highest stresses due to heavy duty usage, the footplates are reinforced with bracing angles so that they give firm stability to the shear. The machine used is called a shear, power shear. The machine may be powered, less commonly hand powered. It works by first clamping the material with a ram, a moving blade then comes down across a fixed blade to shear the material. For larger shears the moving blade may be set on an angle or rocked in order to shear the material progressively from one side to the other, setting the blade on an angle decreases the amount of force required, but increases the stroke. A5 degree shear angle decreases the force by about 20%, the amount of energy used is still the same. The moving blade may also be inclined 0.5 to 2. 5°, called the rake angle, however, raking the blade compromises the squareness of the edge. The machine consists of a table, work-holding device, upper and lower blades. The shear table is the part of the machinery that the workpiece rests on while being sheared, the work-holding device is used to hold the workpiece in place and keep it from moving or buckling while under stress. The upper and lower blades are the piece of machinery that actually do the cutting, the design of press tools is an engineering compromise. A sharp edge, strength, and durability are ideal, but a sharp edge is not very strong or durable, typical workpiece materials include aluminum, brass, bronze, and mild steel because of their outstanding shearability ratings. Stainless steel is not sheared as often due to its tendencies to work-harden, other geometric possibilities include the squaring shear, angle shear, bow-tie shear and bar shear. All of these have different uses and are all used regularly in certain manufacturing fields
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Tipped tool
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A tipped tool generally refers to any cutting tool where the cutting edge consists of a separate piece of material, either brazed, welded or clamped on to a separate body. Common materials for tips include cemented carbide, polycrystalline diamond, tools that are commonly tipped include, milling cutters, tool bits, and saw blades. The advantage of tipped tools is only a small insert of the material is needed to provide the cutting ability. The small size makes manufacturing of the easier than making a solid tool of the same material. This also reduces cost because the tool holder can be made of a less-expensive, in some situations a tipped tool is better than its solid counterpart because it combines the toughness of the tool holder with the hardness of the insert. In other situations this is less optimal, because the joint between the tool holder and the insert reduces rigidity. However, these tools may still be used because the overall cost savings is still greater, inserts are removable cutting tips, which means they are not brazed or welded to the tool body. They are usually indexable, meaning that they can be rotated or flipped without disturbing the overall geometry of the tool. This saves time in manufacturing by allowing fresh cutting edges to be presented periodically without the need for grinding, setup changes. A wiper insert is a used in a milling machine or a lathe. It is designed for cutting, to give a smooth surface on the surface being cut. It uses special geometry to give a finish on the workpiece at a higher-than-normal feedrate. Wiper inserts generally have an area in contact with the workpiece. This makes them unsuitable for fragile workpieces, inserts used for turning and milling are often numbered according to ISO standard 1832. This standard aims to make the naming, specifying and ordering of inserts a simple, consistent and this standard takes into account both metric and imperial systems of units, although certain elements differ for each unit system
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Tool bit
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A tool bit is a non-rotary cutting tool used in metal lathes, shapers, and planers. Such cutters are often referred to by the set-phrase name of single-point cutting tool. The cutting edge is ground to suit a particular machining operation, the ground tool bit is held rigidly by a tool holder while it is cutting. Back rake is to control the direction of the chip. It also helps counteract the pressure against the tool from the work by pulling the tool into the work. Side Rake along with back rake controls the flow and partly counteracts the resistance of the work to the movement of the cutter. Brass for example requires a back and side rake of 0 degrees while aluminum uses a rake of 35 degrees. Nose Radius makes the finish of the cut smoother as it can overlap the previous cut and eliminate the peaks, having a radius also strengthens the tip, a sharp point being quite fragile. All the other angles are for clearance in order that no part of the tool besides the actual cutting edge can touch the work, the front clearance angle is usually 8 degrees while the side clearance angle is 10-15 degrees and partly depends on the rate of feed expected. The Rake angles on the top of the tool need not be precise in order to cut but to cut efficiently there will be an angle for back. Originally, all tool bits were made of carbon tool steels with the appropriate hardening and tempering. Since the introductions of high-speed steel, sintered carbide, ceramic and diamond cutters, most tool bits today are made of HSS, cobalt steel, or carbide. Carbide, ceramics and diamond, having higher hardness than HSS, because these materials are more expensive and brittler than steel, typically the body of the cutting tool is made of steel, and a small cutting edge made of the harder material is attached. The cutting edge is either screwed or clamped on, or brazed on to a steel shank. Almost all high-performance cutting tools use indexable inserts, there are several reasons for this. First of all, at the very high cutting speeds and feeds supported by these materials, economics are also important, inserts are made symmetrically so that when the first cutting edge is dull they can be rotated, presenting a fresh cutting edge. Some inserts are made so that they can be flipped over. There are many types of inserts, some for roughing, some for finishing, others are made for specialized jobs like cutting threads or grooves
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Brake (sheet metal bending)
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A brake is a metalworking machine that allows the bending of sheet metal. A cornice brake only allows for simple bends and creases, while a box-and-pan brake also allows one to form box and it is also known as a bending machine or bending brake or in Britain as a sheet metal folder or just a folder. The brake consists of a surface onto which the material is placed. This clamping action may be manual, automatic or operated using a foot pedal, the front, gate-like, plate of the machine is hinged and may be lifted, forcing the material extended over a straight edge to bend to follow the plate. The bends can be to any angle up to a limit of about 120 degrees. If the area to be bent is narrow enough, a bend can be made by inserting the bend under the clamping bar. A cornice brake has a solid clamping bar, the width of the machine, thus, it can only make straight bends. After bending, a box or pan form is completed by screw, solder, weld, rivet. This is a brake, usually much smaller than cornice or box-and-pan brakes. Typically, a handle both clamps the workpiece and makes the bend, in a single motion, but the depth is usually much less than what a cornice or box-and-pan brake can handle. This is a complex tool that forms predetermined bends by clamping the workpiece between a matching punch and die
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Die (manufacturing)
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A die is a specialized tool used in manufacturing industries to cut or shape material mostly using a press. Like molds, dies are generally customized to the item they are used to create, products made with dies range from simple paper clips to complex pieces used in advanced technology. Forming dies are made by tool and die makers and put into production after mounting into a press. The die is a block that is used for forming materials like sheet metal. For the vacuum forming of sheet only a single form is used. Vacuum forming is considered a simple molding thermoforming process but uses the principles as die forming. The workpiece may pass through several stages using different tools or operations to obtain the final form, the main components for die tool sets are, Die block – This is the main part that all the other parts are attached to. Punch plate – This part holds and supports the different punches in place, blank punch – This part along with the blank die produces the blanked part. Pierce punch – This part along with the pierce die removes parts from the finished part. Stripper plate – This is used to hold the material down on the blank/pierce die, pilot – This will help to place the sheet accurately for the next stage of operation. Guide, back gauge, or finger stop – These parts are all used to make sure that the material being worked on always goes in the position, within the die. Setting block – This part is used to control the depth that the punch goes into the die, Blanking dies – See blanking punch Pierce die – See pierce punch. Shank – used to hold in the presses and it should be aligned and situated at the center of gravity of the plate. Processes, Blanking, A blanking die produces a piece of material by cutting the desired shape in one operation. The finished part is referred to as a blank, generally a blanking die may only cut the outside contour of a part, often used for parts with no internal features. Three benefits to die blanking are, Accuracy, a properly sharpened die, with the correct amount of clearance between the punch and die, will produce a part that holds close dimensional tolerances in relationship to the parts edges. Since the part is blanked in one operation, the edges of the part produces a uniform appearance as opposed to varying degrees of burnishing from multiple operations. Due to the compression of the blanking process, the end result is a flat part that may retain a specific level of flatness for additional manufacturing operations
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English wheel
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The English wheel, in Britain also known as a wheeling machine, is a metalworking tool that enables a craftsperson to form compound curves from flat sheets of metal such as aluminium or steel. The process of using an English wheel is known as wheeling and it is a forming machine that works by surface stretching and is related in action to panel beating processes. English wheel production is at its highest in low-volume sports car production and this cost is defrayed across a larger production run, but a stamping press is limited to only one model of panel per set of dies. The English wheel model shown is manually operated, but when used on thicker sheet metals such as for ship hulls the machine may be powered, the machine is shaped like a large, closed letter C. At the ends of the C, there are two wheels, the wheel on the top is called the rolling wheel, while the wheel on the bottom is called the anvil wheel. The anvil wheel usually has a smaller radius than the rolling wheel, although larger machines exist, the rolling wheel is usually 8 cm wide or less, and usually 25 cm in diameter, or less. The rolling wheel is flat in cross section, while the wheel is domed. The depth of the C-shaped frame is called the throat, the largest machines have throat sizes of 120 cm, while smaller machines have throat sizes of about 60 cm. The C stands vertically and is supported by a frame, the throat size usually determines the largest size of metal sheet that the operator can place in the machine and work easily. On some machines, the operator can turn the top wheel and it may move with a hydraulic jack on machines designed for steel plate, or a jackscrew on machines designed for sheet metals. As the material thins, the operator must adjust the pressure to compensate, frame designs are the most significant element of this simple device. For the most part wheels have changed little since the 19th century. The early English machines, such as Edwards, Kendrick, Brown, Boggs and these wheels, made during the 19th Century, had Babbitt metal plain bearings, making them difficult to push and pull the metal through when operated at high pressures. Later, when ball bearings came into use, the became more suitable for hard and thick material. Despite the advantages of cast iron, it has less than half the stiffness of steel, steel frames made of solid flame-cut plate, or frames built-up of cut-and-welded plates, are common designs. Tube-framed machines are reasonably-priced and are either as kit-built machines. The stiffest tubular frames have a fully triangulated external bracing truss and they are most effective on thinner or softer materials, such as 20 ga steel or.063 aluminum. Cast frame machines, like the one pictured, are still available, a properly equipped machine has an assortment of anvil wheels
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