Step Drill Bit Knoweasy 3Pcs High-Speed Steel Step Drill Set 4-12mm/4-20mm/4-32mm Drill Bits Set Used for Drilling Plate Aluminum Metal Wood Hole Large Hole Drill Suitable for DIY Lovers

【Material】High-speed steel HSS makes the drill bits more capable and durable.Its surface has been polished by the titanium processing so that will reduce friction and run cooler. 【Easy Drilling】Two flute design provides faster smoother and cleaner cuts each step is clearly labeled with the depth diameter in steps. Hex shanks design in order to prevent slippage when in chuck. 【Widely Used】Perfect Step Drill Bits suitable for drill holes in various material： within 3mm/0.12 inch (Iron Plate Copper Plate Aluminum Plate); within 5mm/0.2 inch (Wood PVC sheet Insulation Boards). Not suitable for hard and brittle materials such as stainless steel glass tile floors walls etc. 【Set Includes】Bit 4-32: 15 steps-4mm/6mm/8mm/10mm/12mm/14mm/16mm/18mm/20mm/22mm/24mm/26mm/28m/30m/32mm; Bit 4-20: 9 steps-4mm/6mm/8mm/10mm/12mm/14mm/16mm/18mm/20mm; Bit 4-12: 5 steps-4mm/6mm/8mm/10mm/12mm 【What is Included】 3-Piece HSS Groove Step Drill Bit (4-12/ 4-20/ 4-32mm ). 1/4 Hex shaft drives are suitable for all kinds of for home DIY power drills.