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.OVERALL LENGHT3.0-12.010step6 4.0-12.05step6/6.5554.0-12.09step6/6.5654.0-20.09step8754.0-20.09step10854.0-22.010step10 4.0-30.013step10974.0-30.014step101004. ...