A nail gun, nailgun or nailer is a form of hammer used to drive nails into wood or other materials. It is usually driven by compressed air (pneumatic), electromagnetism, highly flammable gases such as butane or propane, or, for powder-actuated tools, a small explosive charge. Nail guns have in many ways replaced hammers as tools of choice among builders.
Pneumatic nail gun in use
Air compressor supplies air into a nail gun
Pneumatic nail guns require hoses for their compressed air power supply
A piston in the head of a nail gun drives the fastener
A hammer is a tool, most often a hand tool, consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object. This can be, for example, to drive nails into wood, to shape metal, or to crush rock. Hammers are used for a wide range of driving, shaping, breaking and non-destructive striking applications. Traditional disciplines include carpentry, blacksmithing, warfare, and percussive musicianship.
A modern claw hammer suited to drive and remove nails
Cartwheel mallets with heads of felt held between steel washers for use with timpani drums
Detail of the head of a war hammer
A geologist's hammer used to break up rocks, as seen in archaeology and prospecting
