Wide range of applications: Ceramic tile drill bits are suitable for all electric drills. Widely used in glass, ceramic tile, ceramic, floor tile, jade, marble, rosary, granite, etc. Not suitable for tempered glass, concrete or concrete deeper than 1/2. High Quality: The tip of the diamond drill bit is made of nickel-plated high speed steel (HSS) and has a 80-100 grit diamond coating. Fast cutting: the diamond hole saw blade is coated, sharp, high precision, smooth cutting, no bending, easy to cut into a clean hole and precise, the center guide hole and side holes help eliminate waste. Usage: The hole saw glass drill bit tool set is used with all electric drills and impact drills. Please keep the speed at 800-1000 per minute. Keep adding water to keep the drill cool. Dry drilling is strictly prohibited. Package: You will get 15 pieces hole saws, the size is 6mm 8mm 10mm 12mm 14mm 16mm 18mm 20mm 22mm 25mm 26 mm 28mm 30mm 40mm 50mm Quantity and size can meet your daily needs. Specifications: Material: Carbon Steel 15pcs 6mm-50mm Diamond Hole Saw Bit Set Features: This diamond core bit can remove full circle of glass, tile, marble, granite, ceramic or other materials Color: Silver Diamond drill shank diameter is: Diamond drill shank diameter -6mm is 6mm. Shank diameter of -8mm to 25mm diamond drill bit is 8mm. Shank diameter of other diamond drill bits is 10mm. Note: 1. If you smell something burning, step back! Your speed is too high or the pressure is too high. Do not touch the bit you are drilling hot or not even hot. 2. Always use water for lubrication, otherwise the diamond core drill will burn! ! ! 3. Can be used with standard electric drills. 4. Make a semi-circle mark, then keep the drill straight. 5. Reducing the drilling speed, lowering the weight of the bit and increasing the use of water lubrication will greatly extend the life of the bit. 6. Use coolant. 7. Minimum pressure. 8. The general rule is that the smaller the drill diameter, the faster the drill speed that can be used. The harder the material, the slower the drilling speed should be. Package includes: 15*diamond brazing drill bits