"ALUMINUM ALLOY QQ-A-250/4 TEMPER T3,DIM.,1.940 IN. NOM LG,1.900 IN. NOMHEIGHT,0.160 IN. NOM MATERIAL THICKNESS,TWO HOLES 0.315 IN. MIN,0.322 IN.MAX DIA DRILLED THRU ON VERTICAL CENTERLINE 0.400 AND 1.500 IN. FROM TOPW/1.100 IN. DISTANCE BETWEEN CENTERS,CORNERS CHAMFERED 0.470 IN. DEEP ANDWIDE BY 45 DEG,MAX SURFACE FINISH,ALL SURFACES 125 MICROINCHES AA"