3a thread class right-hand 0.391" thread length hexagon head style 0.812" grip length 24 thread quantity per inch cadmium surface treated unf thread series
3a thread class right-hand 0.375" thread length headless (setscrew) head style 20 thread quantity per inch cadmium or chromate surface treated unf thread series
3a thread class right-hand 0.615" thread length headless (setscrew) head style 18 thread quantity per inch navy special project cadmium surface treated unc thread series