This set includes four tools designed for clean chamfers, deburring and countersinking in metal, plastic and other materials. Use with a bench drill for best stability; hand drills can cause wobble and reduce chamfer quality. Includes tapered countersink bits. - Thread chamfer tool: Designed for use with a bench drill to produce accurate chamfers. Using a hand drill may cause wobble and affect chamfering results. Includes tapered countersink drill bits for versatile finishing. - Countersink bit for metal: Made of cobalt steel material for high hardness and rust resistance. Solid and durable, part of a countersink bit kit. - Deburring tool bit: High hardness for smooth chip processing. Suitable for chamfering, deburring and cone processing. - Single end countersink bit: Ideal for cutting through plastic, aluminum, copper, stainless steel, aluminum plate, insulation boards and PVC sheet. Single end countersinks. Applications: - Finish drilled through-holes in aluminum or stainless steel so screw heads sit flush. - Deburr and chamfer edges on metal or plastic parts. - Create clean countersunk holes in PVC sheets or insulation boards for hardware installations.