7/3/1PCS HSS Step Drill Bit Sets Straight Groove Titanium Coated Cone Hole Cutter Auto Center Punch Spiral Twist Saw Drill Bit

Description: [Material]: High-speed steel 4241. [Handle]: Step drill is triangle round handle, prevent sliping. The saw and drill is a round handle. [Surface treatment]: The gold is titanium coating, more wear and oxidation resistance, not rust. [Product use] High-speed steel 4241 material is suitable for iron plate, aluminum alloy, copper plate, wood board, [Specification]:  [Product name] 7PC pagoda drill serrated drill (3 step drills, 3 serrated drills and 1 positioning punch) Drilling and reaming of plastics and other materials 4 - 12 mm 5 Steps (4mm,6mm,8mm,10mm,12mm)  4 - 20 mm 9 Steps (4mm,6mm,8mm,10mm,12mm,14mm,16mm,18mm,20mm) 4 - 32 mm 15 Steps (4mm,6mm,8mm,10mm,12mm,14mm,16mm,18mm,20mm,22mm,24mm,26mm,28mm,30mm,32mm) 3PC Serrated Drill 3, 6, 8mm One brass center punch [Advantages]: 1. "X" shaped openings, drilling is not easy to slip. Higher precision, more sharp, burr-free drilling. 2, The unique step structure, a drill can drill a variety of sizes of the ap