The H4's Nickel Boron EXO Coated Carrier and H&M Nitride treated bolt puts the right materials in the right places. Lifetime Warranty!

AIM H4 AR/M16 5.56/.223/.300 BLACKOUT complete Bolt Carrier Group. Features UCT's exclusive Nickel Boron EXO Technology coating and H&M's BLACKNITRIDE finishes. 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.

UCT’S EXCLUSIVE EXO TECHNOLOGY

EXO Technology creates a competitive advantage for all kinds of components, because treated parts run dramatically longer and more accurately with less maintenance. Further, EXO greatly enhances heat dissipation, so treated products run far cooler than non-treated parts.

The EXO process is permanent, lasting for the entire lifespan of treated parts. A patented, nodular nickel-boron (NiB) surface treatment, EXO nucleates on the surface atoms of metals, becoming part of the metal rather than merely applied to the outside. In addition, the treated surface becomes harder than the substrate itself, eliminating the cost, weight and degradation problems of conventional hardened metals.

EXO Technology is featured in firearms, weapons and support systems used by the U.S. military and law enforcement and security agencies. EXO Technology is appropriate for virtually any application where reduced friction, extended service life, enhanced performance and lower maintenance are desirable.

H&M BLACKNITRIDE

BLACKNITRIDE™, or Ferritic Nitrocarburizing, is the thermochemical that simultaneously diffuses nitrogen and carbon into the surface of ferrous metals. During the process, a two-part surface layer is formed, an outer iron nitride layer with a nitrogen diffusion layer below it. During this treatment, nitrogen and carbon are absorbed by and diffused into the surface of the metal. Reproducible and uniform layers with a predetermined thickness will be formed on all areas of the metal. The result of this process is markedly improved surface properties on ferrous metal parts while maintaining dimensional and shape stability.

Metal components treated with BLACKNITRIDE™ have increased wear-resistance, fatigue strength, corrosion resistance, lubricity and cosmetic appeal. Often replacing the more expensive processes of hard chrome or nickel plating, BLACKNITRIDE™ gives better corrosion protection at equivalent or lower costs. Additionally, BLACKNITRIDE™ is commonly used as an alternative to high temperature conventional heat treatments such as carburizing and carbonitriding.