3a thread class right-hand 0.251" thread length pan head style 2.990" grip length 32 thread quantity per inch cadmium fastener surface treated unjf thread series
3a thread class right-hand 0.371" thread length flat countersunk undercut head style 40 thread quantity per inch passivate surface treated unc thread series
2a thread class right-hand 0.375" thread length flat chamfer head style 24 thread quantity per inch navy special project medium diamond knurl; lathe centers permitted both ends oxide surface treated unc thread series