4340 steel per ams6414; heat treat rockwell c40 min to c45 max.; 0.586 in. Lg o/a; 1.812 in. Hub diameter by 0.469 in. Thk; 51 internal involute sline teethw/30.0 degrees pressure angle by 1.5938 in. Pd by 1.5630 in. Minor diameter by 1.650 in. Major diameter by 0.148 in. Deep
