Material alum aly 6061-t6 per qq-a-250/11 (sm1870-27) or 5052-h32 per qq-a-250/8 (sm1870-21); finish chromate chemical film per mil-c-5541, clia and paint per sd1037-05-36 using color no. 37038 black; outside diam. 3.625 in., 9 mtg holes 4-40 unc-2b thd through per mil-s-7742, drilled 3.250 diameter bsc
