Glass 6 mm -30 mm Diamond Drill Bits Porcelain Diamond Drill Bits Set for Ceramic Tiles Glass Drill Bits 10Pcs Hollow Drill Bits for Ceramic Tiles <p>10 sizes (diameter): 6 mm (1/4""), 8 mm (5/16""), 10 mm (3/8""), 12 mm (1/2""), 15 mm (3/5""), 16 mm (5/8""), 18 mm (11/16""), 20 mm (3/4""), 22 mm (7/8""), 30 mm (1-1/5"). Meet most of your different needs.</p> <p>Stainless and durable: made of high strength carbon steel with a smooth nickel plated surface for long life.</p> <p>Fast, accurate and smooth cutting: coated with high quality diamond to improve drilling speed and create a clean, high precision and smooth cut without broken edges in seconds.</p> <p>Application: drilling glass, tile bottles, block jars, fiberglass porcelain tile ceramic, Mable slate, clear granite stone. Do not use on concrete or for depths greater than approximately 1/2</p> <p>Caution: please keep the speed at 800 to 1,000 per minute, keep adding water to keep the drill cool, strictly prohibit dry drilling.</p> Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Minnanxin