The defense industry uses a variety of equipment that requires heat treatment during the manufacturing process. Firearms used by the military are manufactured under stringent standards to ensure quality and reliability. Heat treat processes are used on components and material used in firearms to ensure they meet industry specifications.

Why heat treatment is a critical step in firearm manufacturing

Firearms are placed under a great deal of pressure during use so it is vital that the materials they are produced with are durable and able to withstand the extreme conditions they will be exposed to. Heat treat furnaces are used to treat metals used in firearm components with processes such as carburizing, nitriding, case hardening, and stress relieving to increase product longevity, reduce stress fractures, and improve their overall strength. The machining of the gun barrels of firearms along with the extreme pressure exerted on the barrel during use make heat treating a critical step in their manufacturing process.

Stress Relieving of Gun Barrels

During the manufacturing process, gun barrels undergo a rifling process that involves machining helical grooves on the internal surface of the barrel. The purpose of rifling is to create torque which causes the spin of the bullet during shooting. Cut rifling and button rifling are two methods used in the industry.

Cut rifling involves the cutting or scraping of the grooves in the steel. Specialized equipment is used to cut and remove small amounts of steel from the barrel while it is slowly rotated to form the twist in the rifling. Button rifling is the most popular method used and creates the grooves by using a bullet-shaped button of tungsten carbide. The rifling button is pushed or pulled through the barrel, which creates the groove pattern on the internal surface of the gun barrel.

These rifling processes cause a significant amount of stress on the gun barrel which if left untreated could lead to splitting and cracking. A stress relieving or normalizing process is used to strengthen the machined gun barrel and relieve the metal of internal stresses caused by rifling. The stress relieving process is dependent on time and temperature. A stress relieving furnace applies heat to the gun barrel for a specified period of time to reduce the residual stress in the material and decreases the risk of dimensional changes or cracking.

Firearms are not the only kind of equipment in the defense industry that require heat treat furnaces during the manufacturing process. Ammunition casings undergo an annealing process and many components in military vehicles such as tanks, trucks, and helicopters have been heat treated. Lindberg/MPH designs and manufactures heat treat furnaces that meet the exacting specifications of the defense industry. To learn more about the furnaces we provide, click here. To discover more, reach out to us on the contact information below, or via Facebook or LinkedIn.