KNS Precision, Inc. .1555 Diameter Non-Rotating Trigger/Hammer Pins, Black NRTHP-1555 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 stainless steel. Black side plates are black nitride treated" all other color options are DuraCoated. An absolute must-have for all M-16 owners. They will also protect your AR-15.