Aluminum alloy, qq-a-200-8, temper t6 or ams4027, rockwell hardness rating rc 30t 49.5, heat treated per mil-h-6088 per united aircraft specification no. Hs454, irregular shape 0.630 in. Min, 0.690 in. Max. High, 0.422 in. Min, 0.482 in. Max deep, 0.750 in. Min, 0.810 in. Max width