Waluminum alloy, qq-a-225/11, finish per mil-c-5541 0.50 in. W, 0.50 in. Diameter large end, 0.130 in. Thk small end, 0.42 in. Lg large end, 0.234 in. Min, 0.235 in. Max diameter serrated hole, 36 teeth, 0.193 in. Min, 0.195 in. Max diameter hole small end