Aluminum alloy, anodized, 0/a dim. 0.250 in. Id, 1.500 in. Od, 0.620 in. Lg, knurled friction face 0.280 in. Lg w/45 degrees bevel, shank end 0.620 in. Diameter by 0.340 in. Lg w/2 holes ctr 0.160 in. From end, one 0.089 in. Diameter through tapped 4-40unc2b, one 0.070 in. Diameter by 0.060 in. Dp