High-quality materials: Our step drill bit is made of high-speed steel and provides fast, comfortable and frictionless drilling; a small case for easy storage and carrying. Titanium coating: The peeling drill bit with titanium coating provides good resistance to corrosion, heat and rust; reduces friction and heat; for a longer service life even at extreme temperatures. 13 drilling sizes: For different hole sizes, you only need one step drill bit; 13 sizes are on the step drill bit for your convenience: 5 mm, 7 mm, 10 mm, 12 mm, 15 mm, 17 mm, 20 mm, 22 mm, 25 mm, 27 mm, 30 mm, 32 mm, 35 mm. Fast drilling: The double blade design provides faster and frictionless cutting. Please note that during the working of the step drill, pour some water to cool the step drill; the service life of the HSS step drill will be effectively extended. Material: The step drill is suitable for household repairs and light work such as drilling holes in plastic, copper, aluminum and many other types of sheet