Steel; 1.875 in. Lg o/a; 6.000 in. Od of flange, 0.625 in. Thk; 4 mtg holes 0.500-20 unf, equally spaced on a 5.000 in. Bolt circle dia; hubs on both sides of flange are identical, 2.937 in. Od, 0.625 in. Lg; 1.750 in. Diameter bore; 1 keyway through bore, 0.375 in. W, 0.187 in. Dp