Used on spec item. 3a thread class right-hand 0.281" thread length button head style 36 thread quantity per inch cadmium surface treated unf thread series
2a thread class right-hand 0.325" thread length flat countersunk head style 40 thread quantity per inch cadmium screw surface treated unc thread series
2a thread class right-hand 0.250" thread length flat countersunk head style 32 thread quantity per inch cadmium screw surface treated unc thread series