Aluminum alloy per qq-a-270 6061-t6; 3.495 in. Dia, 0.485 in. Lg; center hole 1.000 in. Diameter 0.340 in. Lg 2.880 in. Diameter 0.145 in. Lg; 6 holes 0.154 in. Diameter thru; 3 holes 0.127 in. Diameter thru; 3 holes on edge 0.134 in. Diameter 0.535 in. Deep w/0.164-32unc3b thds 0.185 in. Deep