3 Pack 4mm to 20mm Spiral Flute Step Drill Bits High Speed Steel Titanium Coated, Metric Hex Shank, HSS Tool Set for DIY Plastic Wood Metal Aluminum. Cone Cutter Hole

2 flute spiral groove step drill - Gives a good fast and smooth cut. 4-20mm - This metric step drill has 9 steps - 4mm 6mm 8mm 10mm 12mm 14mm 16mm 18mm and 20mm. So you can drill accurate holes to any of these sizes. Suitable for cutting holes in a variety of materials including steel, brass, wood, plastic, aluminum copper, gypsum board, metal material, fiberglass, and PVC etc, convenient to store in bag, car, or at home. Ideal for professional and home use HSS (high speed steel) with a titanium (Tin) coating - The titanium coating makes it easier to drill materials and also gives an improved tool life. Where possible use coolant to increase the tool life even further. 1/4"(6.35mm) hex shank - will fit in any drill with a standard chuck and any pillar drill. Each step is clearly marked with the diameter