Advantage: Classic HSS provides stability and speed. Special titanium coating to reduce friction and heat, durability, and make drilling more precise. Double-slot and depth gauge designs allow for faster, smoother, and more accurate cuts. Perfect drilling of steel, brass, plastic, wood, copper, fiberglass, PVC, thin metal, and aluminum. Specifications: Type: 5-35mm (5,7,10,12,15,17,20,22,25,27,30,32,35mm) Total Length：72mm The height of each step is 3mm Shank Diameter: 12.7mm Shank Length：24mm Material: HSS-4241 Weight: 30g Package Included: 1pcs 13 Step 5mm-35mm HSS Step Drill Bit Hot Tip: Recommended drilling speed 250--400rpm It is made of HSS-4241, can not work on stainless steel suit for use in hardness under HRC 25° artifacts, the plate thickness less than 5mm water to cool it while working, it can effectively extend the service life. Caution: Please remember to protect your hands when using it. This product is not sold to children.