Use: Ideal for sinking 90 degree holes in wood and soft metals Countersunk head screws and fixings. With a shank diameter of 6.35mm and a length of 20mm, can be geared with an electric drill or battery.Unique Process: High quality non-slip wear-resistant ensures greater comfort and convenience, surface treatment: blackening treatmentSize: Commonly used Sizes including 12mm, 16mm and 19mm all with 1/4" hex quick change shanks, angle: 90 degrees. Five flute countersink countersink, heat treatment: high frequency quenching, increase hardnessDurable: High quality high carbon steel, durable and stainless, long service life.Specification:Material: HSSQuantity: 3 PcsShank: 6.35mm (1/4")Size: Approx. 12mm x 43mm, 16mm x 45mm, 19mm x 49mmSurface treatment: Blackening treatmentHeat treatment: high frequency quenching, improve hardnessApplicable scope: Suitable for Chamfering wood plastic chamfering etcFeatures:Suitable for all wood and aluminum 1/4" Quick-change hex shank Suitable for all hand and motor drills Heat-treated carbon steel blades ensure long life Ideal for wood planks, fiberboard, particleboard, plywood, plastic, aluminum panels, etc. to form holes Universally applicable, stepping down and deburring without chatter Suitable for DIY, home and general construction to development Ideal for sinking 90 degree holes in wood and soft metals in the preparation of countersunk head screws and fastenersSet includes all commonly used sizes including 12mm, 1 6mm and 19mm, all with 1/4" hex quick change shanks for easy quick change with a 1/4" quick chuck system