Step drill Use one drill for many holes. Multiple Step and countersink tool for drilling and countersinking in one smooth operation. Size: 4-12mm Step: 1mm Steel: HSS (High-speed Steel) Application: Suitable for materials with a maximum thickness of 4 to 6mm depending on the hardness. The best type of drill for Steel plate. Benefits: Burr free holes. Perfectly round holes. Easy to enlarge holes. Stronger - more rigid. Drills plastic easily. Non-slip points. Tip: The use of cutting paste is recommended. What's in the box 1 x Step Drill HSS 4-12mm x 1mm