2a thread class right-hand 0.175" thread length flat chamfer head style 40 thread quantity per inch straight knurl copper surface treated unc thread series
3a thread class right-hand 0.940" thread length 24 thread quantity per inch unthreaded portion below head 0.180 inch long. shank below second shoulder 0.340 inch min, 0.350 inch max dia; 0.480 inch long unf thread series