2a thread class right-hand 0.162" thread length flat countersunk head style 72 thread quantity per inch navy special project oxide screw surface treated unf thread series
3a thread class right-hand 0.338" thread length hexagon head style 28 thread quantity per inch passivate screw surface treated keyway, chamfered dog point 0.100 in. lg. 0.202 max dia unf thread series
3a thread class right-hand 0.578" thread length flat countersunk head style 24 thread quantity per inch cadmium or cadmium screw surface treated unjf thread series