A knife is a tool with a cutting edge or blade attached to a handle. Mankind's first tool, knives were used at least two-and-a-half million years ago, as evidenced by the Oldowan tools. Made of rock, bone and obsidian, over the centuries, in step with improvements in metallurgy or manufacture, knife blades have been made from bronze, iron, steel and titanium. Most modern knives have either folding blades. Knives can serve various purposes. Hunters use a hunting knife, soldiers use the combat knife, scouts and hikers carry a pocket knife. A modern knife consists of: the blade the handle the point – the end of the knife used for piercing the edge – the cutting surface of the knife extending from the point to the heel the grind – the cross section shape of the blade the spine – the thickest section of the blade. Single-edged knives may have a reverse edge or false edge occupying a section of the spine; these edges are serrated and are used to further enhance function. The handle, used to grip and manipulate the blade safely, may include a tang, a portion of the blade that extends into the handle.
Knives are made with full tangs. The handle may include a bolster, a piece of heavy material situated at the front or rear of the handle; the bolster, as its name suggests, is used to mechanically strengthen the knife. Knife blades can be manufactured from a variety of materials, each of which has advantages and disadvantages. Carbon steel, an alloy of iron and carbon, can be sharp, it holds its edge well, remains easy to sharpen, but is vulnerable to rust and stains. Stainless steel is an alloy of iron, chromium nickel, molybdenum, with only a small amount of carbon, it is not able to take quite as sharp an edge as carbon steel, but is resistant to corrosion. High carbon stainless steel is stainless steel with a higher amount of carbon, intended to incorporate the better attributes of carbon steel and stainless steel. High carbon stainless steel blades do not discolor or stain, maintain a sharp edge. Laminated blades use combining the attributes of both. For example, a harder, more brittle steel may be sandwiched between an outer layer of softer, stainless steel to reduce vulnerability to corrosion.
In this case, the part most affected by corrosion, the edge, is still vulnerable. Damascus steel is a form of pattern welding with similarities to laminate construction. Layers of different steel types are welded together, but the stock is manipulated to create patterns in the steel. Titanium is a metal that has a better strength-to-weight ratio, is more wear resistant, more flexible than steel. Although less hard and unable to take as sharp an edge, carbides in the titanium alloy allow them to be heat-treated to a sufficient hardness. Ceramic blades are hard and lightweight: they may maintain a sharp edge for years with no maintenance at all, but are as fragile as glass and will break if dropped on a hard surface, they are immune to common corrosion, can only be sharpened on silicon carbide sandpaper and some grinding wheels. Plastic blades are not sharp and serrated, they are disposable. Steel blades are shaped by forging or stock removal. Forged blades are made by heating a single piece of steel shaping the metal while hot using a hammer or press.
Stock removal blades are shaped by removing metal. With both methods, after shaping, the steel must be heat treated; this involves heating the steel above its critical point quenching the blade to harden it. After hardening, the blade is tempered to make the blade tougher. Mass manufactured kitchen cutlery uses both the stock removal processes. Forging tends to be reserved for manufacturers' more expensive product lines, can be distinguished from stock removal product lines by the presence of an integral bolster, though integral bolsters can be crafted through either shaping method. Knives are sharpened in various ways. Flat ground blades have a profile that tapers from the thick spine to the sharp edge in a straight or convex line. Seen in cross section, the blade would form a long, thin triangle, or where the taper does not extend to the back of the blade, a long thin rectangle with one peaked side. Hollow ground blades have beveled edges; the resulting blade has a thinner edge, so it may have better cutting ability for shallow cuts, but it is lighter and less durable than flat ground blades and will tend to bind in deep cuts.
A blade is the portion of a tool, weapon, or machine with an edge, designed to puncture, slice or scrape surfaces or materials. Blades are made from materials that are harder than those they are to be used on. Humans have made blades from flaking stones such as flint or obsidian, from various metal such as copper and iron. Modern blades are made of steel or ceramic. Blades are one of humanity's oldest tools, continue to be used for combat, food preparation, other purposes. Blades work by concentrating force on the cutting edge. Certain blades, such as those used on bread knives or saws, are serrated, further concentrating force on the point of each tooth. During food preparation, knives are used for slicing and piercing. In combat, a blade may be used to slash or puncture, may be thrown or otherwise propelled; the function is to sever a nerve, muscle or tendon fibers, or blood vessel to disable or kill the adversary. Severing a major blood vessel leads to death due to exsanguination. Shrapnel causes wounds via the fragments' blade-like nature.
Blades may be used to scrape, moving the blade sideways across a surface, as in an ink eraser, rather than along or through a surface. For construction equipment such as a grader, the ground-working implement is referred to as the blade with a replaceable cutting edge. A simple blade intended for cutting has two faces. Ideally this edge would have no roundness but in practice all edges can be seen to be rounded to some degree under magnification either optically or with an electron microscope. Force is pressing on the back of the blade; the handle or back of the blade has a large area compared to the fine edge. This concentration of applied force onto the small edge area increases the pressure exerted by the edge, it is this high pressure that allows a blade to cut through a material by breaking the bonds between the molecules/crystals/fibres/etc. in the material. This necessitates the blade being strong enough to resist breaking before the other material gives way; the angle at which the faces meet is important as a larger angle will make for a duller blade while making the edge stronger.
A stronger edge is less to dull from fracture or from having the edge roll out of shape. The shape of the blade is important. A thicker blade will be heavier and stronger and stiffer than a thinner one of similar design while making it experience more drag while slicing or piercing. A filleting knife will be thin enough to be flexible while a carving knife will be thicker and stiffer. A curved edge, like a talwar will allow the user to draw the edge of the blade against an opponent while close to the opponent where a straight sword would be more difficult to pull in the same fashion; the curved edge of an axe means that only a small length of the edge will strike the tree, concentrating force as does a thinner edge whereas a straight edge could land with the full length of its edge against a flat section of tree. A splitting maul has a convex section to avoid getting stuck in wood where chopping axes can be flat or concave. A khopesh or falchion or kukri is angled and/or weighted at the distal end so that force is concentrated at the faster moving, heavier part of the blade maximising cutting power and making it unsuitable for thrusting where a rapier is thin and tapered allowing it to pierce and be moved with more agility while reducing its chopping power compared to a sized sword.
A serrated edge, such as on a saw or a bread knife, concentrates force onto the tips of the serrations which increases pressure as well as allowing soft or fibrous material to be expand into the spaces between serrations. Whereas pushing any knife a bread knife, down onto a bread loaf will just squash the loaf as bread has a low elastic modulus but high yield strain, drawing serrations across the loaf with little downward force will allow each serration to cut the bread with much less deformation of the loaf. Pushing on a rope tends to squash the rope while drawing serrations across it sheers the rope fibres. Drawing a smooth blade is less effective as the blade is parallel to the direction draw but the serrations of a serrated blade are at an angle to the fibres. Serrations on knives are symmetric allowing the blade to cut on both the forward and reverse strokes of a cut, a notable exception being Veff serrations which are designed to maximise cutting power while moving the blade away from the user.
Saw blade serrations, for both wood and metal, are asymmetrical so that they cut while moving in only one direction. Fullers are longitudinal channels either forged into the blade or machined/milled out of the blade though the process is less desirable; this loss of material weakens the blade but serves to make the blade lighter without sacrificing stiffness. The same principle is applied in the manufacture of beams such as I-beams. Fullers are only of significant utility in swords. In most knives there is so little material removed by the fuller than it makes little difference to the weight of the blade and they are cosmetic. Ty
Swiss Army knife
The Swiss Army knife is a pocketknife or multi-tool manufactured by Victorinox. The term "Swiss Army knife" was coined by American soldiers after World War II due to the difficulty they had in pronouncing "Offiziersmesser", the German name; the Swiss Army knife has a main spearpoint blade, as well as various tools, such as screwdrivers, a can opener, many others. These attachments are stowed inside the handle of the knife through a pivot point mechanism; the handle is in its stereotypical red color, features a Victorinox or Wenger "cross" logo or, for Swiss military issue knives, the coat of arms of Switzerland. Originating in Ibach, the Swiss Army knife was first produced in 1891 after the company, Karl Elsener, which became Victorinox, won the contract to produce the Swiss Army's Modell 1890 knife from the previous German manufacturer. In 1893, the Swiss cutlery company Paul Boéchat & Cie, which became Wenger, received its first contract from the Swiss military to produce model 1890 knives.
A cultural icon of Switzerland, the design of the knife and its versatility have both led to worldwide recognition. During the late 1880s, the Swiss Army decided to purchase a new folding pocket knife for their soldiers; this knife was to be suitable for use by the army in opening canned food and disassembling the Swiss service rifle, the Schmidt–Rubin, which required a screwdriver for assembly. The Swiss Army Knife was not the first multi-use pocket knife. In 1851 in "Moby Dick", Melville references the "Sheffield contrivances, assuming the exterior - though a little swelled - of a common pocket knife. In January 1891, the knife received the official designation Modell 1890; the knife had a blade, can-opener and grips made out of dark oak wood that some say was partly replaced with ebony wood. At that time no Swiss company had the necessary production capacity, so the initial order for 15,000 knives was placed with the German knife manufacturer Wester & Co. from Solingen, Germany. These knives were delivered in October 1891.
In 1891, Karl Elsener owner of a company that made surgical equipment, set out to manufacture the knives in Switzerland itself. At the end of 1891 Elsener began production of the Modell 1890 knives, in direct competition with the Solingen company, he incurred financial losses doing so, as Wester & Co was able to produce the knives at a lower cost. Elsener was on the verge of bankruptcy when, in 1896, he developed an improved knife, intended for the use by officers, with tools attached on both sides of the handle using a special spring mechanism, allowing him to use the same spring to hold them in place; this new knife was patented on 12 June 1897, featuring a second, smaller cutting blade, a corkscrew, wood fibre grips, under the name of Schweizer Offiziers- und SPortmesser. While the Swiss military did not commission the knife, it was marketed internationally, restoring Elsener's company to prosperity. Elsener used the Swiss coat of arms to identify his knives beginning in 1909. With slight modifications, this is still the company logo.
In 1909, on the death of his mother, Elsener named his company "Victoria", after her given name, in her honour. Elsener managed to control the market until 1893, when the second industrial cutler of Switzerland, Paul Boéchat & Cie, headquartered in Delémont in the French-speaking region of Jura, started selling a similar product; this company was acquired by its general manager, Théodore Wenger, renamed the Wenger Company. In 1908 the Swiss government, wanting to prevent an issue over regional favouritism, but wanting a bit of competition in hopes of lowering prices, split the contract with Victorinox and Wenger, each getting half of the orders placed. By mutual agreement, Wenger has advertised as the Genuine Swiss Army Knife and Victorinox used the slogan, the Original Swiss Army Knife. In 1921, as the company started using stainless steel, Elsener's son, Carl Elsener, renamed the company to "Victorinox", incorporating the abbreviation "inox" for acier inoxydable, the French term for stainless steel.
During 1961–2005, the pocket knives issued by the Swiss military were produced by Victorinox and Wenger. On 26 April 2005, Victorinox acquired Wenger, once again becoming the sole supplier of knives to the Military of Switzerland. Victorinox at first kept the Wenger brand intact, but on 30 January 2013, the company announced that the Wenger brand of knives would be abandoned in favour of Victorinox; the press release stated that Wenger's factory in Delemont would continue to produce knives and all employees at this site will retain their jobs. They further elaborated that an assortment of items from the Wenger line-up will remain in production under the Victorinox brand name. Wenger's US headquarters will be merged with Victorinox's location in Connecticut. Wenger's watch and licensing business will continue as a separate brand: Swiss Gear.. Up to 2008 Victorinox AG and Wenger SA supplied about 50,000 knives to the military of Switzerland each year, manufactured many more for export to the United States.
Many commercial Victorinox and Wenger Swiss Army knives can be distinguished by the cross logos depicted on their grips. Victorinox registered the words "Swiss Army" and "Swiss Milita
A sword is a bladed weapon intended for slashing or thrusting, longer than a knife or dagger, consisting of a long blade attached to a hilt. The precise definition of the term varies with the historical epoch or the geographic region under consideration; the blade can be curved. Thrusting swords have a pointed tip on the blade, tend to be straighter. Many swords are designed for both slashing; the sword developed in the Bronze Age, evolving from the dagger. The Iron Age sword remained short and without a crossguard; the spatha, as it developed in the Late Roman army, became the predecessor of the European sword of the Middle Ages, at first adopted as the Migration Period sword, only in the High Middle Ages, developed into the classical arming sword with crossguard. The word sword continues the Old English, sweord; the use of a sword is known as swordsmanship or, in a modern context, as fencing. In the Early Modern period, western sword design diverged into two forms, the thrusting swords and the sabers.
The thrusting swords such as the rapier and the smallsword were designed to impale their targets and inflict deep stab wounds. Their long and straight yet light and well balanced design made them maneuverable and deadly in a duel but ineffective when used in a slashing or chopping motion. A well aimed lunge and thrust could end a fight in seconds with just the sword's point, leading to the development of a fighting style which resembles modern fencing; the saber and similar blades such as the cutlass were built more and were more used in warfare. Built for slashing and chopping at multiple enemies from horseback, the saber's long curved blade and forward weight balance gave it a deadly character all its own on the battlefield. Most sabers had sharp points and double-edged blades, making them capable of piercing soldier after soldier in a cavalry charge. Sabers continued to see battlefield use until the early 20th century; the US Navy kept tens of thousands of sturdy cutlasses in their armory well into World War II and many were issued to marines in the Pacific as jungle machetes.
Non-European weapons called "sword" include single-edged weapons such as the Middle Eastern scimitar, the Chinese dao and the related Japanese katana. The Chinese jìan is an example of a non-European double-edged sword, like the European models derived from the double-edged Iron Age sword; the first weapons that can be described as "swords" date to around 3300 BC. They have been found in Arslantepe, are made from arsenical bronze, are about 60 cm long; some of them are inlaid with silver. The sword developed from the dagger. A knife is unlike a dagger in that a knife has only one cutting surface, while a dagger has two cutting surfaces; when the construction of longer blades became possible, from the late 3rd millennium BC in the Middle East, first in arsenic copper in tin-bronze. Blades longer than 60 cm were rare and not practical until the late Bronze Age because the Young's modulus of bronze is low, longer blades would bend easily; the development of the sword out of the dagger was gradual.
These are the "type A" swords of the Aegean Bronze Age. One of the most important, longest-lasting, types swords of the European Bronze Age was the Naue II type known as Griffzungenschwert; this type first appears in c. the 13th century BC in Northern Italy, survives well into the Iron Age, with a life-span of about seven centuries. During its lifetime, metallurgy changed from bronze to iron, but not its basic design. Naue II swords were exported from Europe to the Aegean, as far afield as Ugarit, beginning about 1200 BC, i.e. just a few decades before the final collapse of the palace cultures in the Bronze Age collapse. Naue II swords could be as long as 85 cm. Robert Drews linked the Naue Type II Swords, which spread from Southern Europe into the Mediterranean, with the Bronze Age collapse. Naue II swords, along with Nordic full-hilted swords, were made with functionality and aesthetics in mind; the hilts of these swords were beautifully crafted and contained false rivets in order to make the sword more visually appealing.
Swords coming from northern Denmark and northern Germany contained three or more fake rivets in the hilt. Sword production in China is attested from the Bronze Age Shang Dynasty; the technology for bronze swords reached its high point during the Warring States period and Qin Dynasty. Amongst the Warring States period swords, some unique technologies were used, such as casting high tin edges over softer, lower tin cores, or the application of diamond shaped patterns on the blade. Unique for Chinese bronzes is the consistent use of high tin bronze, hard and breaks if stressed too far, whereas other cultures preferred lower tin bronze, which bends if stressed too far. Although iron swords were made alongside bronze, it was not until the early Han period that iron replaced bronze. In the Indian subcontinent, earliest available Bronze age swords of copper were discovered in the Indus Valley Civilization sites in the northwestern regions of South Asia. Swords have been recovered in