Professional Diamond Hole OpenerMade of selected high strength carbon steel and diamond coated drill bit, excellent cutting ability, anti-rust and durable, high torque and long service life. High-quality hole drillingDiamond coating can increase the drilling speed and make the drill sharper. The tip design makes the resistance smaller and more efficient, helping you drill a smooth round hole precisely. Round chip hole on the side to keep the drill clean at all times. Great forDiamond soldering specially designed for porcelain, glass, marble, ceramic, rock and granite , etc. Usage TipsFirstly, you can cut a 45 oblique, open the positioning crescent groove, then slowly erect the hole opener and drill to a uniform speed. In addition, keep the bit moist when drilling to avoid overheating Buy with confidenceIf you have any questions, please feel free to contact us. We will try our best to resolve it for you. (Please clamp the tree in the right place and take necessary protective measures when processing wood).