General description This 3pcs HSS Spiral Groove Peeling Drill Bit Set includes cone drill bits designed for metal, wood, plastic, and more. The set features tapered tips with a step profile that allows for drilling 19 hole sizes ranging from 4mm to 32mm, effectively replacing 19 individual drill bits. The self-starting design eliminates the need for pilot drilling, making it user-friendly. Technical specifications Sizes: 4-12mm, 4-20mm, 4-32mm Material: High Speed Steel (HSS) 4241 Coating: Titanium coated for reduced friction Length: 7cm for 4-12mm and 4-20mm; 10cm for 4-32mm Step sizes: 4-12mm (9 steps), 4-20mm (9 steps), 4-32mm (15 steps) Usage Ideal for cutting holes in various materials including steel, sheet metal, wood, plastic, thin iron, aluminum alloy, insulation board, and PVC film. Automatically deburrs holes as you drill, ensuring a smooth finish. Good chip evacuation and even cutting save time and effort. Other information Scope of delivery: 1 x twist drill 4-12mm, 1 x