Steel, mil-s-6050 or steel, mil-s-6090 or steel, mil-s-6049 or steel, mil-s-6758; cadmium, qq-p-416, type 2, cl 2 or zinc, qq-z-325, type 1, cl 3; 1.250 in. O/a lg; centrally located shoulder 0.420 in. Lg, o.560 in. Dia; 0.418 in. Diameter both ends; threaded hole 1/4-28 unjf 3b lh through center of shoulder