
HSS4241 High Speed Steel Step Drill Bit 10-45 Spiral Step Drill Bits Nitrogen Coated Made of high speed steel and nitrogen coated to reduce friction and run cooler. Spiral cutting flute; automatically deburr holes as you drill. Application: Suitable for workpieces less than 25mm hardness, such as carbon steel, sheet metal, insulation board, PVC board, plank and wood with thickness less than 5mm. 8 levels: 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm.