These are the KNS Precision Inc Generation 2 pin sets. These are the STRONGEST pins that can be produced and were designed to withstand the high impact of full and semi-auto 9mm, .223, and 7.62mm suppressed weapons. The pins are black nitrided stainless steel. End retainers are Black Nitride. An absolute must-have for all M-16 owners. They will also protect your AR-15. Special anti-creep retainers prevent wear on your irreplaceable M-16 or AR-15 receiver. THE TORQUE SPEC ON THE SCREW IS 11 inch/lbs. MAXIMUM. KNS Precision recommends 8INCH/LBS of torque.