Steel, stainless, type 302 per mil-s-7720-1, passivate finish per aes 64186, 0.500 in. Od, 0.182 min, 0.187 max in. W across flats of 0.094 in. Lg shoulder, 0.217 in. Shoulder dia, 0.016 in. Corner r, 0.016 in.X 45.0 degrees chamfer, 0.734 in. O/a lg