Aluminum alloy, qq-a-250/11, 6061-t6; chemical film, mil-c-5541, 1a; 0.250 in. Thk; 0.875 in. Sq, corners 0.130 in. At 45 degrees angle; 2 holes 4-40 unc-2b by 0.250 in. Dp, directly opposite each other along width; 3 holes in face 0.250 in. Dia, 0.350 in. Diameter by 100 degrees csk both sides
