Aluminum alloy 6061-t6 per a11577279; anodize per mil-a-8625 ty i or ii cl 2; 5.00 in. Lg; hex shape 3.76 in. Lg; 1.875 in. Across flats; 1.496 in. Diameter inner shaft; 0.625-11unc-2b internal thd; 1.504 in. Id large end; 0.560 in. Dp; 0.680 in. Id hole small end 0.620 in. Dp