3a thread class right-hand 0.553" thread length dished hexagon head style 0.052" grip length 24 thread quantity per inch cadmium surface treated unjf thread series
3a thread class right-hand 0.400" thread length hexagon head style 28 thread quantity per inch washer under head; thickness 0.015 in. min 0.035 in. max oxide fastener surface treated unjf thread series
3a thread class right-hand 0.491" thread length flat countersunk head style 0.678" grip length 24 thread quantity per inch passivate surface treated unjf thread series