AIM H4 AR/M16 5.56/.223/.300 BLACKOUT complete Black Nitride treated Bolt Carrier Group. A newly designed carrier reduces the surface area contact between the carrier and receiver walls. This improves performance and reliability as it reduces drag and creates "debris" channels to reduce malfunctions. Features 9310 Bolt Material; 8620 carrier; Properly staked machined billet gas key hardened to USGI specifications fastened with Hardened Grade 8 Fasteners; Shot peened MPI (Magnetic Particle Inspected) Bolt. Extractor insert installed. Proudly made in the USA with a Lifetime Warranty.
Black Nitride™ Process Specification and Information:
The Black Nitride™ process represents the most advanced refinement and enhancement of traditional Salt Bath Ferritic Nitrocarburization. AIM Bolt Carrier Group's Black Nitride™ process conforms to all aspects of Aerospace Materials Specification 2753C.
Black Nitride™ is a thermochemical diffusion process whereby nitrogen and carbon are diffused into the surface of the steel resulting in a harder more durable surface. This process is carried out at subcritical temperatures which eliminates any risk of distortion. Additionally, every part is quenched in an oxidizing salt bath proprietary to create a uniform Fe304 oxide layer that is both resistant to corrosion and visually appealing.
For many applications the Black Nitride™ process can replace traditional case hardening. The compound zone surface of Black Nitride™ will have a hardness of 55-70+RC. Depending on the substrate material the compound zone depth will be .0004”-.0008” with an effective case depth of .0004”-.003” and a total case depth that may exceed .010”