Steel 1045, quench and draw to 225-250 brinnel before machining, protective finish u.S. Army specification 57-0-2 type 2, class a, 1.656 in. Lg, 1.750 in. Flange od, 0.156 in. Lg flange, 1.374 in. P0.000 m0.001 od, 1.062 in. Id, onvolute spline 19 teeth in id, worm gear 43 teeth on od under flange