PCS: 6 PCS Countersink Bits are available in six different diameters of 6.3mm/8.3mm/10.4mm/12.4mm/16.5mm/20.5mm. Different diameters can be used for drilling. Sharp Anti-rust This countersink is made of HSS high speed steel, which is high hardness and not easy to rust. Its cutting edge is hardened and ground, so it is sharper and has a longer service life. Note: If you use a countersink drill on a hand drill, use a twist drill to drill the hole, and then use a countersink drill to avoid any risk of shaking caused by drilling. More Processing Materials: 6 PCS walnut countersinks are suitable for chamfering hole edges. The countersinks can process different materials such as hardwood and cork, aluminum foil, plastic, PVC and light iron. This countersink is suitable for all kinds of machine tools. Chamfering Design: The countersink adopts the appropriate inclination angle design, anti-rust and anti-corrosion, beautiful and delicate, giving the sharp edge cutter strength and rigidity, greatly increasing the cutter, the processing properties of cutting and milling. Scope of Application: This countersink drill kit is suitable for home DIY and daily use. It can be drilled easily and efficiently, not only without burrs, but also without scratches. Sturdy and Durable Made from high quality HSS material, this countersink drill bit features high hardness and is not easy to rust. For example, it can be processed on steel plates, wooden boards and plastic plates Multiple Sizes The countersink drill bit has six diameters of 20.5mm, 16.5mm, 12.4mm, 10.4mm, 8.3mm and 6.3mm. A variety of sizes to meet your drilling needs Twist Drill Equipped with a twist drill for positioning, you can use the HSS milling cutter more efficiently and accurately Unique 90 Design The countersink drill adopts a suitable cutting angle design, rust and corrosion resistance, exquisite chamfering, large core diameter, a balance between edge strength and sharpening resistance, increased tool rigidity and the cutting and milling cutting ability, making work more efficient. The countersink bit adopts the appropriate tilt angle design, anti-rust and anti-corrosion, beautiful and delicate, giving the sharp edge cutter strength and rigidity Package List 6 x Countersink Bit: 20.5mm, 16.5mm, 12.4mm, 10.4mm, 8.3mm and 6.3mm Each drill bit has its own package Countersink bits can be used with variety of materials, metal or plastic Countersink bits can work with various mechanical operations Countersink bits can be used with variety of materials, metal or plastic, acrylic, copper, baklite sheets etc Countersink bits can work with various mechanical operations, such as Milling Machine Drill Electric Planer etc