Steel, type 4340 per mas5331, r c 30 min per mil-s-6090 cad plate perqq-p-416 type 11, class 1 or steel type 4330 per mas5329, r c 30 min permil-s-6090 cad plate per qq-p-416 type 11, class 1 or steel, type 17-4phper mas 5343 r c 30 min per mil-h-6875 passivate per mil-f-14072 finishe300 paint all over, except machined areas, with one top coat polyurethaneper mil-c-27227