Professional diamond drill bits for drilling porcelain, glass, hard ceramic tiles and slabs, porcelain, granite marble, quartz, limestone, fiberglass, terrazzo, masonry, stoneware. High-quality, high-temperature resistant diamond drill bits provide efficient and clean drilling. Filled with cooling wax, suitable for dry drilling. However, to extend the service life, it is recommended to use water or coolant. Diameter: 6, 8, 10/12 mm, handle diameter (mm) Usage: Use a screwdriver to drill at a maximum angle of 30°. Then straighten the drill bit and complete a spinner. Wet the bit regularly