Steel, ams6415 alloy, cadmium plate per qq-p-416 type ii, heat treat 38-42rc; 8.00 in. O.D. Of 6 tabs eq spaced 1.63 - 1.64 in. W; 6 holes through 0.276 - 0.290 in. Dia, 5 eq spaced 1 offset on 6.625 in. Bcd; 2 pin holes through 0.3120 - 0.3123 in. Dia; bore diameter 5.384 - 5.394 in.