| Hex Titanium Coated Step Drill Bit Hole Metal Wood Cutter 4-22mm Tool Description: Brand new Type: drill bit Color: golden Material: Surface: titanium coated Features: Design, Useful Tool, 4-22mm Cutter Standard: 4-22mm (4, 6, 8, 10, 12, 14, 16, 18, 20, 22mm) The ladder of its unique structure, a bit can open a variety of specifications of aperture Do not need to use center punch, compared with drill is not easy to be brokenDeburring, chamfering, elliptic hole enlargement, drill, the function of them was unable, but it is possible The use of tools: drill, bench drill. Work while water , can effectively extend the service life of drill bit, recommend drilling rate of 250-250 RPM | |