4130 steel; 22 splines; major diameter 2.285 in. Min 2.290 in. Max; minor diameter 1.995 in. Min; pitch diameter 2.200 in.; pressure angle 30 deg; o/a lg 0.750 in.; square drive 0.506 in. Min, 0.513 in. Max; grooved to accept and furnished with ms16624-231 retaining rings