Products IncludeThese countersink drill bit are available in 6 different diameter sizes, including 6mm(1/4''), 8mm(5/16''), 9mm(3/8''), 12mm(1/2''), 16mm(5/8'') and 19mm(3/4''). And length of countersink drill bit is 6.35mm (1/4 inch hexagonal handle). High QualityThe hex shank countersink tools are made of speed steel.HSS countersunk drill bit has high hardness and toughness. Chamfering tool kit is coated with titanium alloy, anti-rust and long service life. Easy to UseThe 5 flute 90 degree drill has a five-blade chamfer design, no chattering, and the serrations are staggered to ensure that the chips flow freely and freely without obstruction, reduce vibration, make drilling smoother and easier to use. To Eliminate Chatter & VibrationThe drills are hardened and polished to improve clarity. With chatter-free design and staggered cutting teeth, and it can provide a rapid chatter-free cutting. Wide ApplicationChamfering drill hex shank is mainly used for reaming, chamfering, screw head and so on. Also suitable for carbon steel, thin iron plate, plywood, acrylic.