1. Professional diamond hole saw Made of selected high - strength carbon steel, the drill bit is coated with diamond, which has good cutting ability, is rust - proof and durable, with high torque and a relatively long service life. 2. Drilling performance The diamond coating can increase the drilling speed and make the drill bit sharper. The tip design reduces resistance and improves efficiency, helping to accurately drill smooth round holes. There are circular chip removal holes on the side to keep the drill bit clean. 3. Scope of application Specifically designed for diamond welding of materials like porcelain, glass, marble, ceramics, rocks, and granite. 4. Usage tips First, you can cut a 45 - degree bevel and open a positioning crescent groove, then slowly erect the hole saw and drill at a constant speed. In addition, keep the drill bit wet during drilling to avoid overheating. 5. Customer service If you have any questions, please feel free to contact us. We will try to solve them for you. (When processing wood, please properly clamp the workpiece and take necessary protective measures.)