2a thread class right-hand 0.344" thread length flat countersunk head style 32 thread quantity per inch cadmium screw surface treated unc thread series
2a thread class right-hand 0.312" thread length undercut universal head style 40 thread quantity per inch navy special project passivate surface treated unc thread series
3a thread class right-hand 0.560" thread length round w/wrench flats chamfered head style 16 thread quantity per inch counterbore unthreaded unf thread series
3a thread class right-hand 0.251" thread length flat countersunk head style 32 thread quantity per inch cadmium screw surface treated unf thread series