These are in stock and shipping free! They are coated by and purchased directly from Toolcraft.
Toolcraft Black Nitride AR15 Bolt Carrier Group is a M16 Full Auto BCG, manufactured using a 9310 steel bolt, and a 8620 steel carrier.
Material: 8620 Steel
Type: M16 Full Auto (Preferred for most AR-15 builds)
Gas Key Material: 4130 Steel; Grade 8 Gas Key Screws
Coating: Black Nitride
Bolt Material: 9310 Steel
Extractor Material: 4140 Steel
Mil-Spec Gas Rings (3)
Cam Pin Material: 8620 Steel
Firing Pin Material: 416 Stainless Steel
Other: MPI Inspected
*Manufacturers Description of Coating*
Black Nitride is a process commonly referred to as SBN (Salt bath nitride) and QPQ (quench polish quench). These are a form of nitrocarburizing or a Thermo Chemical treatment that improves wear resistance and corrosion resistance of ferrous metals with little or no dimensional change which causes the hardening of steel. The chemical bath results in a deep dark black with a harder, more durable finish.