Stainless steel, ams 5643; protective finish 5.4.1 of mil-std-171; part shall be heated at a temp between +350 degrees f and 400 degreesf for 5 hours min. Then air cooled to room temp; 0.875 in. Dia; 0.320 in. H; contains 1 hole 0.437in. Dia. And conterbored 0.562 in. Dia