Used on f16acft. 3a thread class right-hand 0.338" thread length pan head style 0.125" grip length 32 thread quantity per inch cadmium surface treated unjf thread series
2a thread class right-hand 2.375" thread length hexagon head style 20 thread quantity per inch make from p/n B1821BH050F250, nsn 5305-00-719-5240 zinc surface treated unf thread series
3a thread class right-hand 0.475" thread length bevel-conical head style 0.037" hole diameter 28 thread quantity per inch cadmium surface treated unjf thread series