Powder-actuated tool

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Ramset powder-actuated tool Powder Actuated Tool.jpg
Ramset powder-actuated tool

A powder-actuated tool (PAT, often generically called a Hilti gun or a Ramset gun after their manufacturing companies) is a type of nail gun used in construction and manufacturing to join materials to hard substrates such as steel and concrete. Known as direct fastening or explosive fastening, this technology is powered by a controlled explosion of a small chemical propellant charge, similar to the process that discharges a firearm.

Contents

Features

Low-velocity powder-actuated tool cross section Powder Actuated Tool Diagram.png
Low-velocity powder-actuated tool cross section

Powder-actuated tools are often used because of their speed of operation, compared to other processes such as drilling and then installing a threaded fastener. They can more easily be used in narrow or awkward locations, such as installing steel suspension clips into an overhead concrete ceiling.

Powder-actuated tools are powered by small explosive cartridges, which are triggered when a firing pin strikes a primer, a sensitive explosive charge in the base of the cartridge. The primer ignites the main charge of powder, which burns rapidly. The hot gases released by the burning of the propellant rapidly build pressure within the cartridge, which pushes either directly on the head of the fastener, or on a piston, accelerating the fastener out of the muzzle.

Powder-actuated tools come in high-velocity and low-velocity types. In high-velocity tools, the propellant charge acts directly on the fastener in a process similar to a firearm. Low-velocity tools introduce a piston into the chamber. The propellant acts on the piston, which then drives the fastener into the substrate. The piston is analogous to the bolt of a captive bolt pistol.

A tool is considered low velocity if the average test velocity of the fastener is not in excess of 300 ft/s (91 m/s) with no single test having a velocity of over 108 m/s (350 ft/s). [1] A high velocity tool propels or discharges a stud, pin, or fastener in excess of 300 ft/s (91 m/s). [1]

High-velocity tools made or sold in the United States must comply under certain circumstances; [2] with many being used in the shipbuilding and steel industries.

Powder-actuated fasteners are made of special heat-treated steel; common nails are unsafe for this application. There are many specialized fasteners designed for specific applications in the construction and manufacturing industries.

History

Powder-actuated technology was developed for commercial use during the Second World War, when high-velocity fastening systems were used to temporarily repair damage to ships. In the case of hull breaches, these tools fastened steel plates over damaged areas. [3] These tools were developed by Mine Safety Appliances, for the United States Navy. [4] Powder-actuated tools were investigated and used prior to this development; they were used in anti-submarine warfare during the First World War and were the subject of a 1921 United States patent (US Patent No. 1365869). [5]

Types

A Ramset powder actuated fastener tool and supplies. The colored straws in the tray contain cartridges that are loaded singly into the tool. Also visible are 75 mm hardened steel nails with 8 mm heads. Ramset-gun.jpg
A Ramset powder actuated fastener tool and supplies. The colored straws in the tray contain cartridges that are loaded singly into the tool. Also visible are 75 mm hardened steel nails with 8 mm heads.

Powder actuated tools can be variously classified:

Energy sources

Strip-fed cartridges for a nail gun Blankcartridge.jpg
Strip-fed cartridges for a nail gun

Powder-actuated tools are powered by specially-designed blank firearm cartridges, also informally called "loads", "boosters", "rounds", or "charges".

In many cases, the charges are ordinary firearm cartridges with modified casings, and the bullets omitted. The .22 Short, developed by Smith & Wesson, is common. These charges may be hand-fed (single-shot), or manufactured and distributed on a plastic carrier strip.

Color coding

Powder-Actuated Drive Pins, one fitted with an orange-colored sabot Fastener Example 1.jpg
Powder-Actuated Drive Pins, one fitted with an orange-colored sabot
Yellow sabot near the tip of the round Fastener Example 2.jpg
Yellow sabot near the tip of the round
In brass-colored casings:
Color codingVelocity
Gray315 ft/s (96 m/s)
Brown385 ft/s (117 m/s)
Green490 ft/s (150 m/s)
Yellow575 ft/s (175 m/s)
Red675 ft/s (206 m/s)
Purple755 ft/s (230 m/s)
In nickel (silver-colored) casings:
Color codingVelocity
Gray845 ft/s (258 m/s)
Brown935 ft/s (285 m/s)
Green1,025 ft/s (312 m/s)
Yellow1,115 ft/s (340 m/s)
Red1,205 ft/s (367 m/s)
Purple1,295 ft/s (395 m/s)

The three single-shot strengths or colors typically sold to the general public are brown, green, and yellow in brass-colored casings.

Not all powder-actuated tools are rated for high-capacity charges—the strongest charge (nickel-purple at 1,295 ft/s (395 m/s)), for example, is dangerous in a tool not rated for the high pressures it generates. The table above is for a 350-grain (23 g) slug from a test device.[ citation needed ]

Safety and regulation

As with their air-actuated cousins, powder-actuated guns have a muzzle safety interlock. If the muzzle is not pressed against a surface with sufficient force, the firing pin is blocked and cannot reach the load to fire it. This helps ensure that the gun does not discharge in an unsafe manner, causing the nail to become an unrestrained projectile.

Due to their potential for causing personal injury, OSHA regulations in the US require certification specific to the tool being used before any person is permitted to rent or use powder-actuated equipment. [6] Most manufacturers of powder-actuated nail guns offer training and certification, some with free online testing. In addition, special instruction is necessary if the prospective user is unable to distinguish colors used in the color code system that identifies proper power levels. Most certifications are accepted for life; however, in California they must be renewed every three years. [7]

See also

Related Research Articles

<span class="mw-page-title-main">Firearm</span> Gun for an individual

A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries.

<span class="mw-page-title-main">Cartridge (firearms)</span> Ammunition consisting of a casing, projectile, propellant, and primer

A cartridge, also known as a round, is a type of pre-assembled firearm ammunition packaging a projectile, a propellant substance and an ignition device (primer) within a metallic, paper, or plastic case that is precisely made to fit within the barrel chamber of a breechloading gun, for convenient transportation and handling during shooting. Although in popular usage the term "bullet" is often used to refer to a complete cartridge, the correct usage only refers to the projectile.

A muzzleloader is any firearm, in which the user loads the projectile and the propellant charge into the muzzle end of the gun. This is distinct from the modern designs of breech-loading firearms, in which user loads the ammunition into the breech end of the barrel. The term "muzzleloader" applies to both rifled and smoothbore type muzzleloaders, and may also refer to the marksman who specializes in the shooting of such firearms. The firing methods, paraphernalia and mechanism further divide both categories as do caliber.

<span class="mw-page-title-main">Air gun</span> Gun that uses compressed air to launch projectiles

An air gun or airgun is a gun that using energy from compressed air or other gases that are mechanically pressurized and released as propellant for the chosen projectiles based on the principle of the primitive blowgun. This is in contrast to a firearm, which fires projectiles using energy by burning combustible propellants, most often gunpowder.

Muzzle velocity is the speed of a projectile with respect to the muzzle at the moment it leaves the end of a gun's barrel. Firearm muzzle velocities range from approximately 120 m/s (390 ft/s) to 370 m/s (1,200 ft/s) in black powder muskets, to more than 1,200 m/s (3,900 ft/s) in modern rifles with high-velocity cartridges such as the .220 Swift and .204 Ruger, all the way to 1,700 m/s (5,600 ft/s) for tank guns firing kinetic energy penetrator ammunition. To simulate orbital debris impacts on spacecraft, NASA launches projectiles through light-gas guns at speeds up to 8,500 m/s (28,000 ft/s). FPS and MPH are the most common American measurements for bullets. Several factors, including the type of firearm, the cartridge, and the barrel length, determine the bullet's muzzle velocity.

<span class="mw-page-title-main">Centerfire ammunition</span> Type of ammunition common in higher-caliber firearms

A centerfire cartridge is a firearm metallic cartridge whose primer is located at the center of the base of its casing. Unlike rimfire cartridges, the centerfire primer is typically a separate component seated into a recessed cavity in the case head and is replaceable by reloading.

<span class="mw-page-title-main">Rimfire ammunition</span> Type of ammunition common in low-caliber firearms

Rimfire ammunition is a type of firearm metallic cartridge whose primer is located within a hollow circumferential rim protruding from the base of its casing. When fired, the gun's firing pin will strike and crush the rim against the edge of the barrel breech, sparking the primer compound within the rim, and in turn ignite the propellant within the case. Invented in 1845, by Louis-Nicolas Flobert, the first rimfire metallic cartridge was the .22 BB Cap cartridge, which consisted of a percussion cap with a bullet attached to the top. While many other different cartridge priming methods have been tried since the mid-19th century onwards, such as pinfire, only small caliber rimfire and centerfire cartridges have survived to the present day with regular usage. The .22 Long Rifle rimfire cartridge, introduced in 1887, is by far the most common ammunition in the world today in terms of units sold.

<span class="mw-page-title-main">Gun barrel</span> Firearm component which guides the projectile during acceleration

A gun barrel is a crucial part of gun-type weapons such as small firearms, artillery pieces, and air guns. It is the straight shooting tube, usually made of rigid high-strength metal, through which a contained rapid expansion of high-pressure gas(es) is used to propel a projectile out of the front end (muzzle) at a high velocity. The hollow interior of the barrel is called the bore, and the diameter of the bore is called its caliber, usually measured in inches or millimetres.

<span class="mw-page-title-main">.22 Long Rifle</span> Common ammunition cartridge

The .22 Long Rifle or simply .22 LR or 22 is a long-established variety of .22 caliber rimfire ammunition originating from the United States. It is used in a wide range of rifles, pistols, revolvers, and submachine guns.

Internal ballistics, a subfield of ballistics, is the study of the propulsion of a projectile.

<span class="mw-page-title-main">Blank (cartridge)</span> Firearms filler device that produces an explosion but does not fire a projectile

A blank is a firearm cartridge that, when fired, does not shoot a projectile like a bullet or pellet, but generates a muzzle flash and an explosive sound like a normal gunshot would. Firearms may need to be modified to allow a blank to cycle the action, and the shooter experiences less recoil with a blank than with a live round. Blanks are often used in prop guns for shooting simulations that have no need for ballistic results, but still demand light and sound effects, such as in historical reenactments, special effects for theatre, movie and television productions, combat training, for signaling, and cowboy mounted shooting. Specialised blank cartridges are also used for their propellant force in fields as varied as construction, shooting sports, and fishing and general recreation.

<span class="mw-page-title-main">Smokeless powder</span> Type of propellant

Smokeless powder, also referred to as gunpowder, is a type of propellant used in firearms and artillery that produces less smoke and less fouling when fired compared to black powder. The combustion products are mainly gaseous, compared to around 55% solid products for black powder. In addition, smokeless powder does not leave the thick, heavy fouling of hygroscopic material associated with black powder that causes rusting of the barrel.

The .30-06 Springfield cartridge, 7.62×63mm in metric notation, and called the .30 Gov't '06 by Winchester, was introduced to the United States Army in 1906 and later standardized; it remained in military use until the late 1970s. The ".30" refers to the caliber of the bullet in inches, .300 and the "06" refers to the year the cartridge was adopted, 1906. It replaced the .30-03, 6mm Lee Navy, and .30-40 Krag cartridges. The .30-06 remained the U.S. Army's primary rifle and machine gun cartridge for nearly 50 years before being replaced by the 7.62×51mm NATO and 5.56×45mm NATO, both of which remain in current U.S. and NATO service. It remains a very popular sporting round, with ammunition produced by all major manufacturers.

<span class="mw-page-title-main">.22 CB</span>

The .22 CB cap is a more powerful version of the .22 BB cap rimfire metallic cartridge, which was invented by Louis-Nicolas Flobert in 1845. The .22 BB cap and .22 CB cap are interchangeable and are relatively quiet, low velocity cartridges, designed for indoor target shooting.

Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is pushed to the rear by expanding gas created by the ignition of the propellant charge.

<span class="mw-page-title-main">Nail gun</span> Type of power tool

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.

This article explains terms used for the British Armed Forces' ordnance (weapons) and ammunition. The terms may have slightly different meanings in the military of other countries.

The following are terms related to firearms and ammunition topics.

In firearms and artillery, the primer is the chemical and/or device responsible for initiating the propellant combustion that will propel the projectiles out of the gun barrel.

<span class="mw-page-title-main">Silencer (firearms)</span> Device which reduces sound intensity or muzzle flash on a firearm

A silencer, also known as a sound suppressor, suppressor, or sound moderator, is a muzzle device that suppresses the blast created when a gun is discharged, therefore reducing the acoustic intensity of the muzzle report and jump, by modulating the speed and pressure of the propellant gas released from the muzzle. Like other muzzle devices, a silencer can be a detachable accessory mounted to the muzzle, or an integral part of the barrel.

References

  1. 1 2 "Rule 4123:1-3-12 - Ohio Administrative Code | Ohio Laws". codes.ohio.gov. Retrieved 2023-05-15.
  2. "1915.135 - Powder actuated fastening tools. | Occupational Safety and Health Administration". www.osha.gov. Retrieved 2023-05-15.
  3. "Engineering maintenance". Hospital Management. 90: 52. 1960.
  4. "Powder-actuated driver". The Signalman's Journal. 29–30. 1948.
  5. "Powder-actuated fasteners". Engineering Journal. 40–41: 99. 2003.
  6. Use of Powder Actuated Tools Requires Training and Certification
  7. Michael Skube (June 2001). "What you need to know about POWDER-ACTUATED TOOLS". Rental Management Group. Archived from the original on 2016-09-21.