2a thread class right-hand 0.099" thread length flat chamfer head style 56 thread quantity per inch undercut 0.020 wide to 0.070 dia between shoulder passivate surface treated unc thread series
2a thread class right-hand 0.188" thread length flat chamfer head style 56 thread quantity per inch passivate screw surface treated undercut 0.030 in. wide to depth of thread unc thread series