3a thread class right-hand 0.361" thread length flat chamfer head style 32 thread quantity per inch navy special project passivate surface treated unc thread series
2a thread class right-hand 0.464" thread length fillister head style 0.031" hole diameter 56 thread quantity per inch passivate screw surface treated unc thread series
3a thread class right-hand 0.688" thread length crowned hexagon head style 0.031" grip length 28 thread quantity per inch cadmium or chromate surface treated unf thread series