Steel, fed qq-s-633, composition fs1020 to fs1030, triangular shaped, 1/2 in. Thk material, 8-1/2 in. Lg by 5.608 in. W at one end w/two 13/16 in. Diameter holes and 4 in. W at opposite end w/one 2 in. Diameter hole countersunk 90 degrees to 2-1/4 in. Dia