Diamond Drill Bits Tile Glass Hole Opener Saw Cutter Tool Bits 6-32mm Silver 10PCS Descriptions: Tile Hole Puncher with Center Drill Diamond Hole Saw Tools for Glass/Tile/Porcelain/Marble/Ceramic 16mm to32mm Accurate Hole Puncher is made of high carbon steel with a neat and smooth opening,no broken edges. Rustless and Durable Nickel plating on the surface for extended service life and enhanced surface corrosion resistance. The universal round handle is suitable for electric drills and impact drills. Use for The hole opener with a positioning center drill makes drilling easier. Accurate Hole Puncher is perfect for drill glass, tile bottles, fiberglass porcelain tile ceramic, slate mable, granite light stone and other hard material. Important Note: This product can not drill tempered glass Please check the integrity of the hole opener before use. Clamp the hole inserter when it is installed in the drill. When using, first position the 45 bevel drill. Drill vertically again. Due to the drilling, the center drill position can not enter the water, which makes the center drill bit easy to burn out. After the positioning is completed, the center drill bit must be taken down. After the center drill is removed, the drilling efficiency is high. It is necessary to continuously add water to cool during use. So as not to burn the drill bit to extend the life of these hole saws. Wear protective gloves, glasses, masks, etc. when opening the hole, pay attention to safety. Package includes: 1x Drilling bit10pcs