6+1 PCS: 6 PCS Chamfer Cutters are available in six different diameters of 6.3mm/8.3mm/10.4mm/12.4mm/16.5mm/20, 5mm.Various diameters can be used for drilling.Twist drill bit for positioning precise, especially for burying screw heads. Sharp Anti-RustThis cutter is made of HSS high speed steel, which is high hardness and not easy to rust. Its cutting edge is quenched and ground, so it is sharper and has a longer service life.NoteIf you use a drill countersunk head drill on a hand drill, use a twist drill to drill the hole, then use a countersunk drill to avoid any risk of sloshing caused by drilling. More Processing Materials: 6 PCS countersinks in walnut can chamfer the edges of the holes. The countersinks can process different materials such as hardwood and cork, aluminum foil, plastic, PVC and light iron. This chamfer cutter is suitable for all kinds of machine tools Chamfering design: The chamfering cutter adopts the appropriate inclination angle design, anti-rust and anti-corrosion, beautiful and delicate, giving the strength and rigidity of the sharp-edged cutter, the strong increase of the milling cutter, the processing properties of cutting and milling. Scope of application: This countersunk head 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.