Toolcraft Black Nitride 5.56 BCG

The Toolcraft Black Nitride BCG takes the proven reliability of Toolcraft's OEM manufacturing and enhances it with a low-maintenance surface treatment. Black nitride, also known as salt bath nitride (SBN) or QPQ (quench-polish-quench), is a thermochemical treatment that case-hardens the steel surface with minimal dimensional change. This process produces a deep black finish that is harder, more durable, and more corrosion-resistant than traditional phosphate coatings.

The nitride treatment penetrates the steel surface rather than simply coating it, resulting in a finish that won't chip, flake, or peel under hard use. The case-hardened surface is extremely wear-resistant and notably slick, reducing friction and minimizing the need for heavy lubrication. Carbon buildup wipes away easily compared to phosphate finishes, making post-range cleaning significantly faster and requiring fewer harsh solvents.

This current buyable black-nitride SKU uses a 9310 steel bolt paired with an 8620 steel carrier. The bolt is shot peened and MPI inspected, and the carrier includes forward-assist serrations for standard AR-15/M16 compatibility. For shooters who want Toolcraft's proven value with enhanced maintenance characteristics and superior corrosion resistance, the black nitride finish offers a meaningful upgrade for a modest price increase.