3a thread class right-hand 1.540" thread length flat chamfer head style 16 thread quantity per inch 0.745 in dia of unthreaded portion of shank unf thread series
2a thread class right-hand 0.375" thread length headless (setscrew) head style 20 thread quantity per inch cadmium or zinc surface treated unf thread series
3a thread class right-hand 0.703" thread length headless (setscrew) head style 20 thread quantity per inch unthreaded portion casehardened 0.003 to 0.005 in. deep to rc 60 to rc 65, 0.375 in. plus 0.125 in. minus 0 lg phosphate surface treated unc thread series
Used on spec item. 3a thread class right-hand 1.500" thread length headless (setscrew) head style 20 thread quantity per inch cadmium surface treated unc thread series