hex hss spiral grooved step drill set ()<br />drop forged， heat treated， high speed steel， fully polish<br />take the guessing out of drilling by supplying the proper depth for you<br /><br />specifications:<br />color: golden (as picture shown)<br />material: high speed steel<br />quantity: 1pc<br />#1: 4mm to 12mm 9 steps (4mm， 5mm，6mm，7mm，8mm， 9mm，10mm，11mm，12mm)<br />#2: 4mm to 20mm 9 steps (4mm， 6mm， 8mm， 10mm， 12mm， 14mm， 16mm，18mm，20mm)<br />#3: 4mm to 32mm 15steps (4mm， 6mm， 8mm， 10mm， 12mm， 14mm， 16mm， 18mm， 20mm， 22mm， 24mm，26mm，28mm，30mm，32mm)<br />length:<br />4mm to 12mm 9 steps length: 7cm<br />4mm to 20mm 9 steps length: 7.3cm<br />4mm to 32mm 15 steps length: 10cm<br /><br />package includes:<br />1 x step drill bit<br />