By rapidly and precisely firing out nails, nail guns do the work of a hammer easily and efficiently. They are used by professional carpenters for their ease and precision, as well as in the construction industry and for various do-it-yourself home repairs. Different guns are used for different applications, and they don't always use the same kind of nails or nail sizes. Nail guns can be pneumatically driven by an air compressor or battery-powered and cordless. Cordless nail guns have a replaceable gas cartridge filled with butane, a flammable gas. An electrical current from the battery powers a spark plug, which causes a small explosion in a combustion chamber that ignites the gas. The explosion powers the piston, which releases the nail and drives it forward and into the material being fastened. Gas pressure gives consistent nail drive and speed at low velocity.
Cordless nail guns are especially convenient for use in cramped spaces where there is limited mobility. They are lightweight and have an easy grip that is essential for extended use. Cordless framing nail guns are used in the construction industry, and one fuel cell can drive about 1,200 nails. A full battery can discharge up to 400 nails, two to three nails per second. Cordless finish nail guns that are used for carpentry, woodwork, trim and molding can shoot out about 400 nails per hour. More expensive models can fire out up to five nails per second, in both hard and soft surfaces.
The high speed of the nail gun makes it a very dangerous tool; the result is much like shooting bullets from a gun. Therefore, safety measures are of the essence, especially wearing protective gear eye.