step drill, hss step drill, rotary files, reamer, rotary burrs, HSS step drill, step drill bit, countersink drill bit TOTAL-CN TOOLS CO., LTD. is producing cutting tools, step drills, hss step drill, step drill bits: HOLE SIZESTEPSHANK DIA ... .0-40.016step1310520.0-30.011step139730.0-40.011step1397 HSS step drill