3a thread class right-hand 0.302" thread length hexagon head style 0.062" hole diameter 28 thread quantity per inch cadmium surface treated unf thread series
3a thread class right-hand 0.280" thread length hexagon head style 32 thread quantity per inch 0.350 in. min 0.370 in. max dia by 0.130 in. deep countersink in head unf thread series