Nail gun
Encyclopedia
A nail gun, nailgun or nailer is a type of tool
Tool
A tool is a device that can be used to produce an item or achieve a task, but that is not consumed in the process. Informally the word is also used to describe a procedure or process with a specific purpose. Tools that are used in particular fields or activities may have different designations such...

 used to drive nails
Nail (engineering)
In woodworking and construction, a nail is a pin-shaped, sharp object of hard metal or alloy used as a fastener. Formerly wrought iron, today's nails are typically made of steel, often dipped or coated to prevent corrosion in harsh conditions or improve adhesion...

 into wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

 or some other kind of material. It is usually driven by electromagnetism
Electromagnetism
Electromagnetism is one of the four fundamental interactions in nature. The other three are the strong interaction, the weak interaction and gravitation...

, compressed
Gas compressor
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas...

 air (pneumatic), highly flammable gases such as butane
Butane
Butane is a gas with the formula C4H10 that is an alkane with four carbon atoms. The term may refer to any of two structural isomers, or to a mixture of them: in the IUPAC nomenclature, however, butane refers only to the unbranched n-butane isomer; the other one being called "methylpropane" or...

 or propane
Propane
Propane is a three-carbon alkane with the molecular formula , normally a gas, but compressible to a transportable liquid. A by-product of natural gas processing and petroleum refining, it is commonly used as a fuel for engines, oxy-gas torches, barbecues, portable stoves, and residential central...

, or, for powder-actuated tools, a small explosive charge
Pyrotechnics
Pyrotechnics is the science of using materials capable of undergoing self-contained and self-sustained exothermic chemical reactions for the production of heat, light, gas, smoke and/or sound...

. Nail guns have in many ways replaced hammer
Hammer
A hammer is a tool meant to deliver an impact to an object. The most common uses are for driving nails, fitting parts, forging metal and breaking up objects. Hammers are often designed for a specific purpose, and vary widely in their shape and structure. The usual features are a handle and a head,...

s as tools of choice among builders.

Usage

Nail guns do not use individual fasteners. Instead, the fasteners are mounted in long strips (similar to a stick of staples) or collated in a paper or plastic carrier, depending on the design of the nailgun. Some full head nail guns, especially those used for pallet making and roofing, use long plastic or wire collated coils. Some strip nailers use a clipped head so the nails can be placed closer together, which facilitates less frequent reloading. Clip head nails are sometimes banned by state or local building codes. Full Round Head nails provide greater resistance to pull out as do ring shank nails. Nailers may also be of the 'coil' type where the fasteners come in either wire or plastic collation the advantage being a lot more fasteners per load, however, at the expense of extra weight. Industrial nailers designed for use against steel or concrete may have a self-loading action for the explosive caps, but most require nails to be loaded by hand. Nail guns vary in the length and gauge (thickness) of nails they can drive.
The smallest size of fasteners are normally 23 gauge (0.025 inches in diameter)commonly called "pin nailers" and generally have no head. They are used for attaching everything from beadings, mouldings and so forth to furniture all the way up to medium sized (7 to 8 inch) baseboard, crown molding and casing. Lengths are normally in the range ⅜ to 1¼ in. (10 to 32 mm) although some industrial tool manufacturers supply up to 2 in. (50 mm. The 23 gauge micro pin is rapidly gaining ground as users find that it leaves a much smaller hole than brad nails, thereby eliminating the time normally taken to fill holes while at the same time presenting a far better looking finished product.

The next size up is the 18 gauge (1.22 mm diameter) fixing, often referred to as a "brad nail". These fastenings are also used to fix mouldings but can be used in the same way as the smaller 22 to 24 gauge fastenings. Their greater strength leads to their use in trim carpentry on hardwoods where some hole filling is acceptable. Whilst most 18 gauge brads have heads, some manufacturers do offer headless fastenings. Lengths range from ⅝ in to 2 in. (16 mm to 50 mm)

Going up from 18 gauge fastenings the next sizes are 16 and 15 gauge (1.63 and 1.83 mm diameter). These are generally referred to a "finish nails". They come in lengths between ⅝ and 2½ in. (16 to 64 mm) and are used in the general fixing of much softwood and MDF trim work (such as baseboard/skirtings, architraves, etc.) where the holes will be filled and the work painted afterwards.

The largest sizes of conventional collated fastenings are the clipped head and full head nails which are used in framing, fencing and other forms of structural and exterior work. These nails generally have a shank diameter of 0.11 to 0.13 in. (2.9 to 3.1 mm) although some manufacturers offer smaller diameter nails as well. General lengths are in the range 2 in to in (50 to 90 mm). Shank styles include plain, ring annular, twisted, etc. and a variety of materials and finishes are offered including plain steel, galvanized steel, sherardised steel, stainless steel, etc. depending on the pull-out resistance, corrosion resistance, etc. required for the given application. These sizes of fastenings are available in stick collated form (often 20° to 21° for full head, 28° to 34° for clipped head) or coil form (for use in pallet/roofing nailers) depending on the application. Full-head nails have greater pull-out resistance than clipped head nails and are mandated by code in many hurricane zones for structural framing.

Another type of fastening commonly found in construction is the strap fastening which is roughly analogous to the large head clout nail. These are used in conjunction with a strap shot nailer (or positive placement nailer UK) to fix metalwork such as joist hangers, corner plates, strengthening straps, etc. to timber structures. They differ from conventional nailers in that the point of the fastening is not sheathed so it can be exactly positioned before firing the nail gun.

Other specialist nailers are also available which can drive spikes up to 6¼ inches long, fix wood to steel, etc.

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 will not fit and is flexible enough to drive either short nails into metal straps or six inch nails into timber. By repeated hammer action (of around 40 hits per second) the fastener is driven into the material by a more constant palm pressure (as opposed to a conventional nailgun which drives the nail against the inertia of the nailgun itself).

Safety

In the United States, about 37,000 people every year go to emergency rooms with injuries from nail guns, according to the U.S. Centers for Disease Control
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...

 (CDC). Forty percent of those injuries occur to consumers. Nail gun injuries tripled between 1991 to 2005. Foot and hand injuries are among the most common. The U.S. Consumer Product Safety Commission
Consumer Product Safety Commission
The United States Consumer Product Safety Commission is an independent agency of the United States government created in 1972 through the Consumer Product Safety Act to protect "against unreasonable risks of injuries associated with consumer products." The CPSC is an independent agency that does...

 estimates that treating nail gun wounds costs at least $338 million per year nationally in emergency medical care, rehabilitation, and workers' compensation. Often personnel selling the tools know little about the dangers associated with their use or safety features that can prevent injuries.

Injuries to the fingers, hand and foot are among the most common, but there are also injuries that involve other body areas and internal organs. Some of these injuries are serious and some have resulted in death.

All kinds of nail guns can be dangerous, so safety precautions similar to those for a firearm
Firearm
A firearm is a weapon that launches one, or many, projectile at high velocity through confined burning of a propellant. This subsonic burning process is technically known as deflagration, as opposed to supersonic combustion known as a detonation. In older firearms, the propellant was typically...

 are usually recommended for their use. For safety
Safety
Safety is the state of being "safe" , the condition of being protected against physical, social, spiritual, financial, political, emotional, occupational, psychological, educational or other types or consequences of failure, damage, error, accidents, harm or any other event which could be...

, nail guns are designed to be used with the muzzle touching the target. Unless specifically modified for the purpose, they are not effective as projectile weapons.

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 could be prevented through the use of a sequential-trip trigger, according to the CDC.

There is recoil associated with the discharge of a nail from a nail gun. Contact triggers allow the gun to fire unintended nails if the nose hits the wood surface or a previously placed nail following recoil. Nailers with touch tip (contact) triggers are susceptible to this double firing. According to a 2002 engineering report from the Consumer Products Safety Commission (CPSC), the recoil and firing of the second nail occurs well before the trigger can be released. Acute injury rates are twice as high among users of tools with contact triggers.

In September 2011 The Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH) issued a nail gun safety guide that details practical steps to prevent injuries including use of tools with sequential triggers, training prior to use, and use of appropriate protective equipment such as eye protection .

Research aimed at reducing nail gun accidents among frame carpenters, among the heaviest users of nail guns, is ongoing.

Powder actuation

Explosive-powered ("powder actuated") nailguns fall into two broad categories:
  • Direct drive or high velocity devices. This uses gas pressure acting directly on the nail to drive it.
  • Indirect drive or low velocity devices. This uses gas pressure acting on a heavy piston which drives the nail. Indirect drive nailers are safer because they cannot launch a free-flying projectile even if tampered with or misused, and the lower velocity of the nails is less likely to cause explosive shattering of the work substrate.


Either type can, with the right cartridge loads, be very powerful, driving a nail or other fastener into hard concrete, stone, rolled steelwork, etc., with ease.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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