2a thread class right-hand 0.184" thread length flat countersunk head style 24 thread quantity per inch passivate screw surface treated end of screw machined to 0.125 in. dia extending 0.180 in. from thd end unc thread series
2a thread class right-hand 0.170" thread length pan head style 40 thread quantity per inch navy special project passivate screw surface treated paint fed std 595 color no. 36231 unc thread series
3a thread class right-hand 0.553" thread length dished hexagon head style 3.490" grip length 24 thread quantity per inch soft material in threads for locking feature cadmium surface treated unjf thread series