- Huyett Marketing Department
- 09/02/2021
A gun is a complex tool constructed from many moving parts and various materials, each selected for its particular characteristics. The goal is a reliable and durable firearm that fires whenever the trigger is pulled while the safety is off. The parts of a gun have evolved over the centuries as our engineering knowledge increased and our materials science — particularly metallurgy — advanced. In this article, we're going to explore what guns are made of, including the metals used in gun manufacturing, the major components of a gun, and the
firearms fasteners that hold it all together.
What is Gunmetal?
A modern gun may include many different materials: woods, plastics, carbon fiber, and even ceramics. But metal remains the primary material, especially for frames and receivers, the chamber and barrel, and the fire control group. The term "gunmetal" is frequently used to describe metals used in gun manufacturing. However, modern firearms are made of many different metals, each chosen for specific properties of hardness, machinability, durability, and cost?
The original gunmetal was a variety of bronze, an alloy of copper, tin, and zinc. It is also referred to as red brass. This copper alloy is still used in applications where its corrosion‑resistant qualities are valuable, although rarely in firearms. The vast majority of guns are primarily composed of various types of carbon steel, although they may also include stainless steel, aluminum, and other alloys.
It's safe to say that most of the critical components of modern guns you come across will be made of steel. But the name "steel" does not denote one metal; it is a broad category of iron alloys with a precisely calibrated quantity of carbon and other metallic and non‑metallic elements, including nickel, chromium, cobalt, molybdenum, and tungsten.
Carbon Steel
The amount of carbon in steel influences its hardening characteristics. Broadly speaking, carbon steel is available in low‑carbon (also called mild), medium‑carbon, and high‑carbon varieties. These have between 0.3% and 0.75% carbon. As the carbon increases, so does the steel's hardness and strength. However, increased hardness decreases the steel's ductility, machinability, and weldability. High‑carbon steel is also more brittle. That makes high‑carbon steel unsuitable for many applications in cost‑effective gun manufacturing, which tends to use mild and medium carbon steels to strike a balance between hardness and machinability.
Common carbon steels used in gun manufacturing include:
- 4140 steel, also called ordinance steel, has 0.4% carbon and chromium, manganese, and other metals in smaller quantities. 4140 steel is a hard and durable steel used in many gun components such as barrels, bolts, and receivers.
- 4150 steel is similar to 4140 but with a higher proportion of carbon. It is harder than 4140 but also more difficult and expensive to machine, so it is more often used in military‑spec firearms.
- 1020 or 1520 carbon steel is low carbon steel. It is softer and often used in gun components that experience lower stresses, such as trigger guards and sights.
Although these are the most frequently used carbon steels, you will also come across firearms that include other varieties, including the proprietary Carpenter 158, which is used to make the bolts in some guns that follow military specifications.
Stainless Steel
In addition to carbon steel, gun manufacturers may also use stainless steel. Stainless steel is a rust and heat‑resistant iron alloy that contains a large proportion of chromium and other elements such as nickel and molybdenum. As with carbon steel, there are many types of stainless steel with varying properties that depend on the mix of elements added to the iron.
Aluminum Alloys
While most gun components that experience significant forces are made of steel, some parts may be made of anodized aluminum alloys. The most widely used aluminum alloy is 6061 aluminum, also called aircraft aluminum, which contains magnesium and silicon. 6061 aluminum is often used for secondary chambers and suppressors. The stronger 7075 aluminum alloy is used in some receivers — the AR‑15, for example. However, it is more often used in military applications than consumer firearms.
Titanium
Finally, some manufacturers use titanium, which is stronger than aluminum but lighter than carbon steel. Titanium is not as strong as carbon steel, and titanium parts are more expensive to manufacture. It is not often used for parts that experience significant forces, such as the barrel or bolt. There are guns made mainly of titanium, but they are much more expensive than steel guns, and, for the most part, a gun will contain only a few small titanium components, such as parts of the frame, fasteners, and revolver cylinders.
The Parts of a Gun
We've looked at the materials that guns are made of, but how are they used to form a working firearm? There are many different types of firearms, from massive artillery pieces to pocket pistols, with various designs and purposes. Our non‑exhaustive breakdown covers the major components of consumer‑grade firearms, what they do, and what they are made of.
Receiver / Frame
The receiver, or frame when referring to handguns, is the part of the gun that houses and supports the other components. It contains the trigger mechanism and "receives" the barrel, stock, sights, and so on. Receivers are typically made of steel or aluminum, and they are manufactured through stamping, machining, or forging.
Action
In modern repeating action firearms, the action is the mechanism that loads a cartridge from the magazine, fires it, extracts the casing from the chamber, and ejects it from the gun. The may be manual, in which case the user cycles the action after firing, or automatic. Automatic actions use the energy generated during firing to complete the cycle. There are many different action designs; they are often complex mechanisms with many moving parts, levers, springs, and fasteners. They are most often made of carbon steel, stainless steel, and spring steel.
Fire Control Group
The fire control group or trigger group collects components that include the hammer or striker, the safety mechanism, and the sear. The sear holds back the hammer or bolt and, therefore, the firing pin, until the trigger is activated. In short, they are the components that cause the gun to fire when you pull the trigger. The fire control group is usually made of steel, but it may also contain aluminum or titanium components.
Chamber
The chamber holds the cartridge before it is fired. Revolvers have a multi‑chambered cylinder into which the user inserts cartridges, whereas pistols and rifles have a single chamber integrated into the back portion of the barrel. The chamber is exposed to significant forces during firing, and so it is usually made of strong carbon steel.
Barrel
The barrel is the tubular component through which the projectile travels when fired. The chamber is at the barrel's rear, and, after entering the chamber through the breech, the projectile travels through the bore and exits through the muzzle at the firearm's front.
The barrel experiences extreme forces during firing from the rapid expansion of high‑pressure gasses and the projectile's passage. The gun barrel must be able to contain these forces through many hundreds of firings. It is typically made from carbon steel or stainless steel, although some barrels in sports and competition firearms use a thinner metal barrel with an exterior carbon fiber sleeve.
Magazine
A gun's magazine stores ammunition until it is inserted into the chamber via the breech. Magazines may be integrated or detachable. Detachable magazines are often referred to as clips, although clips may be more narrowly defined as magazines that do not include an integrated feed mechanism. The correct terminology is disputed. Detachable magazines are often made of inexpensive stamped metal as they are not exposed to the same extreme forces as the gun's other components.
Firearms Fasteners
We've covered the materials used by gun manufacturers and the major gun parts, but another component group is just as important: firearm fasteners. Firearm fasteners hold the other components together. Without them, a gun is just a pile of parts. We'll conclude this article by looking at some of the firearms fasteners used by gun manufacturers and gunsmiths.
Pins
Pins are short cylindrical metal or plastic fasteners used to align and hold components in place. Many different types of pins are used in firearms manufacturing, including:
- Dowel Pins: Cylindrical rods to align or join components.
- Spring Pins and Roll Pins: Tubular pins with a slot that generates a spring force when inserted into a smaller diameter hole.
- Groove Pins: Solid pins with grooves or flutes that pinch shut when the pin is pressed into a hole, generating a force that holds the pin in place.
- Taper Pins: Pins that taper down their length. Taper pins are held in place by friction.
- Detent Pins: Pins with a captive sprung ball bearing at one end. Detent pins are easily inserted and removed while providing adequate holding force for many applications.
Huyett stocks firearms pins in carbon steel, stainless steel, alloy steel, Monel, brass, and other materials.
Push-On Fasteners and Retaining Rings
This is a diverse category of fasteners used to retain parts in place on shafts, pins, and studs and to create anchor points.
- Palnut Push‑Ons: Single‑piece engineered fasteners for use with round, threaded, or custom studs.
- Snap Rings: Retaining rings that secure components onto grooved shafts or pins.
- Rectangular Retaining Rings: Retaining rings with a rectangular cross‑section, often used to retain parts on a shaft or within a bore.
- E‑Clips: A wide‑shouldered radial clip with prongs to fit into machined grooves on tubes, pins, and shafts.
Huyett stocks hundreds of Push‑On Fasteners, Retaining Rings, Shims, and related parts and fasteners used in the firearms industry. Among the many materials used are carbon steel, stainless steel, spring steel, beryllium copper, and plastic.
Washers and Shims
Washers and shims play several roles in firearms manufacturing as spacers, to distribute the load from fasteners, to preload other parts, and more.
- Shim Rings: Also called tolerance rings, shim rings are fitted to bearings to prevent axial movement and form a buffer between components.
- Variable Shims: Used to increase or decrease the effective length of shafts or bolts.
- Belleville Washers: Spring washers that pre‑load joints and bearings.
- Lock Washers: Toothed bearing lock washers and split lock washers help to prevent the loosening of screws and bolts.
Our washers and shims are manufactured from alloy steel, carbon steel, stainless steel, and spring steel.
Other Firearms Fasteners, Parts, and Tools
In addition to the fasteners we've already discussed, gun manufacturers and gunsmiths also employ numerous other small parts to assemble guns, create anchor points, and aid with construction.
- Flange Bearings are oil‑impregnated bushings designed to support loads while allowing a shaft to rotate freely within the bearing.
- Lock Nuts are designed to resist loosening when exposed to vibration and other forces. They include metal or plastic that deforms when the nut is fitted, creating friction forces that hold the nut in place more effectively than free‑spinning nuts.
- O‑Rings are gaskets that create a gas or liquid seal at the interface between mating parts.
We stock over 100,000 standards compliant firearms fasteners and firearms tools such as hex keys. They are available in a wide variety of materials, finishes, and heat treatments. Our firearms fasteners are used throughout the gun manufacturing and gunsmith industries in firearms, ammunition, optics, and firearms accessories.
To learn more, visit our
firearms fasteners page or
contact our Sales Team for sourcing guidance, engineering support, and information about custom manufacturing.
Huyett is strategically positioned in the supply chain to offer dynamic services to our customers. From master distribution to manufacturing, we easily adapt to our customers' needs, providing valuable industry insight with exceptional customer service. If you have questions about the services we offer,
contact us today to speak with our experienced and friendly Sales Team!
