General description Made of high hardness 4241 high-speed steel (HSS) with a tough titanium coating, this set of 4 countersink drill bits is designed for strength and durability. The bits are suitable for drilling into materials with a hardness below 28 degrees, including plastic, wood, and soft metals. They are ideal for both professional and amateur use in repair and DIY woodworking projects. Technical specifications Material: 4241 high-speed steel (HSS) Titanium coating for enhanced durability Shank sizes: 6mm, 8mm, 10mm, 12mm Chamfer sizes: 2-5mm (2-5 mm x 45 mm), 5-10mm (5-10mm x 47mm), 10-15mm (10-15mm x 62mm), 15-20mm (15mm-20mm x 82mm) Installation Step One: Drill a pilot hole in wood or plastic to guide a screw and increase the size according to the tap. Step Two: Install the chamfering tool on the drill press. For a 16mm hole, use the 15-20mm chamfering device. Step Three: Create a clearance hole by screwing in until horizontal. Note: This drill bit must be used with a drill