2a thread class right-hand 0.470" thread length hexagon head style 0.062" hole diameter 24 thread quantity per inch cadmium surface treated unf thread series
3a thread class right-hand 0.281" thread length fillister head style 0.046" hole diameter 20 thread quantity per inch passivate surface treated unc thread series
3a thread class right-hand 0.375" thread length headless (setscrew) head style 28 thread quantity per inch cadmium or zinc surface treated unf thread series