Professional Diamond Hole Opener Made of high-strength carbon steel with a diamond-coated drill bit, offering excellent cutting performance, rust resistance, durability, high torque, and long service life. High-quality hole drilling: The diamond coating enhances drilling speed and sharpness. The tip design reduces resistance for more efficient and precise drilling, creating smooth, round holes. Features a side chip hole to keep the drill clean during use. Ideal for use on porcelain, glass, marble, ceramic, stone, and granite. Usage Tips: Start by making a 45-degree angle cut to create a positioning groove, then slowly position the hole opener upright and drill at a consistent speed. Keep the bit moist during drilling to prevent overheating. Buy with confidence: If you have any questions, please . We are committed to helping resolve any issues. (Always secure the material properly and use appropriate protective measures when working.)