The AR-15 barrel nut wrench size is designed for a 20-hole pattern barrel nut with a radius of 0.78 inches. It is constructed of 3/8-inch drop forged steel with 6 steel tightening pins and can be used with a 3/8 or a 1/2 driven torque wrench. This crows foot barrel nut wrench is specifically designed for the AR15, M16, and M4 USGI mil-spec standard barrel nut built to military specifications.
