Usage: Ideal for sinking 90 degree holes in wood and soft metals Countersunk screws and fasteners. With 6.35mm Shank Diameter. Unique Process: anti-slip wear-resistant ensures increased comfort and convenience, Surface Treatment: Blackening Treatment Size: Commonly used Sizes including 12mm, 16mm and 19mm all with 1/4" hex quick change shanks, Angle: 90 degrees. Five Flutes Chamfer Countersink, Heat Treatment: High Frequency Quenching, Increase Hardness Durable: high carbon steel, durable and rustproof, long service life. Specification: Material: HSS Quantity: 3 Pcs Shank: 6.35mm (1/4") Size: Approx. 12mm x 43mm, 16mm x 45mm, 19mm x 49mm Surface Treatment: Blackening Treatment Heat Treatment: High Frequency Quenching, Improve Hardness Applicable Scope: Suitable for Wood Plastic Chamfering Chamfering etc Features: Suitable for all wood and aluminum 1/4" Quick Change Hex Shank Fits all hand and power drills Heat treated carbon steel blades ensure good service life Ideal for wood boards, plates fiberboard, particle board, plywood, plastic, aluminum panels, etc. to form holes Universally applicable, chatter-free countersinking and deburring suitable for DIY, home and general construction to development Ideal for sinking 90 degree holes in wood and soft metals in preparation for countersunk screws and fasteners The set includes all commonly used sizes including 12mm, 16mm and 19mm, all with 1/4" hex quick-change shanks for easy quick change with a 1/4" quick chuck system Contents: 1 Set Peripheral Chamfer Drill Bit (3pcs)