1Made of decent high-speed steel, high strength, long service life. 2Unique step construction for good deburrig, chamfering, opening round hole. 3Fast speed, small shaking, can open a beautiful aperture out. 4While working, water injection cooling can effectively extend the service life of the drill bit, the recommended drilling speed is 250-400 RPM. 5Suitable for use in hardness under 25 artifacts, such as iron plate, aluminum plate, PV board, insulation board.
