| HIGH-QUALITY MATERIALS: Our step drill is made of high-speed steel, providing fast, comfortable, and smooth drilling. Titanium Coated: The titanium coated taper drill bit has good resistance to corrosion, heat and rust. reduces friction and heat; for longer life even at extreme temperatures. 13 Sizes of Drill Bits: You only need step drill bits for different hole sizes. There are 13 sizes on the step drill: 5mm, 7mm, 10mm, 12mm, 15mm, 17mm, 20mm, 22mm, 25mm, 27mm, 30mm, 32mm, 35mm. Fast Drilling: The double blade design allows for faster and smoother cutting. Please note that when working on the step drill, pour water to cool the step drill. The service life of the HSS step drill is effectively … | |