"ALUMINUM ALLOY QQ-A-225/9 7075-T73,ANODIC TYPE 2 COATED,3.2425IN. MIN. TO 3.2428 IN. MAX DIA,0.8120 IN. MIN TO 0.8125 IN.MAX THK,MACHINED SURFACES AS NOTED 16.0 32.0 AND 125.0 MICROINCH FINISH,2 HOLES0.261 IN. DIA BY 0.590 IN. DEEP TAPPED 1/4-28 3B THD"