2a thread class right-hand 0.275" thread length 1.335" overall length 20 thread quantity per inch 0.364 in. min, 0.374 in. max dia of shoulder, 0.560 in. min, 0.565 in. max shoulder lg round, closed unc thread series
3a thread class right-hand 1.000" thread length flat chamfer head style 0.044" hole diameter 28 thread quantity per inch cadmium surface treated unrf thread series