3a thread class right-hand 0.371" thread length spline drive shear head head style 28 thread quantity per inch passivate surface treated unjf thread series
3a thread class right-hand 0.441" thread length spline drive shear head head style 24 thread quantity per inch passivate surface treated unjf thread series
3a thread class right-hand 0.742" thread length spline extended washer head style 20 thread quantity per inch passivate surface treated unjf thread series
3a thread class right-hand 0.555" thread length hexagon head style 20 thread quantity per inch concentric hole in head dia. 0.250 in.; depth of hole 0.650 in. unjf thread series