Matl steel, sae 1015, painted mil-t-704, type a, 12.000 in. Lg, 10.000 in. W, 4 mounting holes 0.281 in. Dia, corners 0.750 in. Radius, 4 holes 2.093 in. Dia, 4 holes 1.000 in. Dia, 8 holes 0.188 in. Dia, 4 holes 0.250 in. Dia, 2 holes 0.688 in. Dia, 1 hole 3.500 in. X 2.156 in. Dia