Ssteel, fed specification qq-s-741, 0.250 in. Thk, triangular shaped with rounded corners, approx 8.250 in. W by 6.500 in. Lg, with 0.750 in. Thk boss welded on each corner, 6 holes 0.344 in. Diameter and 1 slot 0.375 in. By 1.125 in. Through surface