ALUMINUM ALLOY QQ-A-325 OR QQ-A-270 6061-T6;ANODIZED MIL-A-8625;0.890 IN. MIN 0.910 IN. MAX LG;1.390 IN. MIN 1.410 IN. MAX FLANGE OD;0.890 IN. MIN 0.910 IN. MAX BOSS OD;0.560 IN. MIN 0.580 IN. MAX BORE ID;FOUR 0.146 IN. MIN 0.151 IN. MAX DIA MTG HOLES ON 1.174 IN. DIA BOLT CIRCLE