Steel per ams6414, comp 4340; heat treat rockwell c40 min to c45 max.; trianglular shape; 0.865 in. Lg o/a by 1.140 in. Hub diameter by 0.350 in. Thk; 39 internal involute spline teeth w/30.0 degrees pressure angle by 0.9750 in. Pd by 0.950 in. Minor diameter by 1.020 in. Major diameter o/a
