Made of high hardness 4241 high speed steel (HSS) and coated with tough titanium, the drill bits are strong and durable Shank: 6mm, 8mm, 10mm, 12mm; Size: 2-5mm, 5-10mm, 10-15mm, 15-20mm Perfectly drill into materials with hardness less than 28 degrees, such as plastic, wood, soft metals , etc. These drill bits can be used for chamfering the workpiece opening and taper-shaped hole Ideal for professional or hobby repair and DIY Size (chamfer size x length) 2-5mm(2-5mm x 45mm) 5-10mm(5-10mm x 47mm) 10-15mm(10-15mm x 62mm) 15-20mm(15mm-20mm x 82mm) < /p> Product Details This titanium coated 90 chamfer tool is suitable for chips to extract and prevents metal chips from springing out and rounding shanks. Wide range of applications Suitable for artifacts under 25 years old, such as thin panels, such as wood, PVC panels, sheets foil, insulating plates or thin plastic sheets, etc. Step one: pilot hole First drill the hole in wood or plastic to locate or guide a screw and increase the size to suit 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 bevel cutter on the drill press. If you need to chamfer a 16mm hole, you can choose a 15-20mm chamfering device. Add water or cutting oil to cool down when chamfering. Third step: clearance hole Finally, screw up horizontally. This drill bit needs to use the drill press, it is easy to shake, and it will affect the chamfering effect if you use the hand drill.