Made of high hardness high speed steel (HSS) 4241 and with tough titanium coating, the bits are strong and durable Shank: 6mm, 8mm, 10mm, 12mm; Size: 2-5mm, 5-10mm, 10-15mm, 15-20mm Drill perfectly in materials with a hardness less than 28 degrees, such as plastic, wood, soft metals, etc. These drills can be used to chamfer the workpiece opening and tapered hole Ideal for professional or amateur repair and DIY Size (chamfer size x length) 2-5mm (2-5 mm x 45 mm) 5-10mm (5-10 mm x 47 mm) 10-15mm (10-15 mm x 62 mm) 15-20mm (15mm-20mm x 82mm) Product Details This titanium coated 90 chamfer tool is suitable for shavings to extract them and prevents metal shavings from gushing out and rounding the shanks. Wide range of applications Suitable for artifacts less than 25 years old, such as thin panels, such as wood, PVC panels, aluminum foils, insulation boards or thin plastic sheets, etc. First step: pilot hole Drill the hole in wood or plastic first to locate or guide a screw and increase the size according to the faucet. Without a pilot hole, the screw may become too tight and break the material or break the screw completely. Step two: Install the chamfer tool Install the chamfer cutter on the drill press. If you need to chamfer a 16mm hole, you can choose a 15-20mm chamfer device. Add water or cutting oil to cool when chamfering. Third step: clearance hole Finally, screw until horizontal. This drill bit must use the drill press, it is easy to shake, and it will affect the chamfering effect if you use the hand drill.