A nail gun, nailgun or nailer is a type of tool used to drive nails into wood or some other kind of material. It is usually driven by electromagnetism, compressed air (pneumatic), 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 amongst builders.
Nail guns often do not use individual nails. Instead, the nails are mounted in long strips (similar to a stick of staples) or in a plastic carrier coil, depending on the design of the nailgun. Some strip nailers use a clipped head so the nails can be placed closer together, which necessitates less frequent reloading. Industrial nailers designed for use against steel or concrete may have a self-loading action for the explosive caps, but require nails to be loaded by hand. Nail guns vary in the length and gauge (thickness) of nails they can drive. Smaller nail guns are often called brad nailers, bradders, or pin nailers, and drive nails with no head. Finish nailers drive smaller gauge nails, over a wide range of lengths, with very small heads. Strap nailers drive 1.5" to 2.5" (38.1mm to 63.5mm) nails for metal connectors used to increase structural strength on wood framed buildings. Framing nailers typically drive 8d to 16d nails, and timber nailers drive spikes up to 6.25 inches long. Roofing nailers, almost always coil-loaded, drive large headed nails that decrease the risk of the nail tearing through the material being secured. Nail guns also have many advantages over hammers as they quickly and repeatedly drive the fastener and consistently set the nail head at, or below, the surface.
A variation on the nail gun is the palm nailer which is a lightweight handheld pneumatic nailer that straps to the hand. It is convenient for working in tight spaces where a conventional nailer won't fit and is flexible enough to drive either short nails into metal straps or six inch nails into timber. To drive a nail you place the head in the magnetic nose, position the tip of the nail at the desired spot, and apply pressure from the palm in the direction of nail travel. The palm pressure triggers a repeated hammer action of around 40 hits per second. Once pressure is removed, or the nail reaches the maximum depth, the nailer shuts off.
All kinds of nail guns can be dangerous, so safety precautions similar to those for a firearm are usually recommended for their use. For safety, nail guns are designed to be used with the muzzle touching the target; they are short-range and inaccurate if a user tries to use one as a projectile weapon (out of the box).
The most common firing mechanism is the dual-action contact-trip trigger, which requires that the manual trigger and nose contact element both be depressed for a nail to be discharged. The sequential-trip trigger, which is safer, requires the nose contact to be depressed before the manual trigger, rather than simultaneously with the trigger. Approximately 65% to 69% of injuries from contact-trip tools likely could be prevented through use of a sequential-trip trigger instead, according to the CDC. When using a nail gun it is important to note that the safety features above are there for a reason. Actions such as leaving the trigger depressed while just using the tip as the triggering device can lead to serious injury.
Explosive-powered ("powder actuated") nailguns fall into two broad categories:
Either type can, with the right cartridge loads, be very powerful indeed, driving a nail or other fastener into hard concrete, stone, or rolled steelwork with ease.
Some areas of the world may need registration, secure storage or other measures to regulate the possession and use of nailguns.