Product Description:DURABLE LIFE:Diamond Hole Drill Bit Sethas the feature of extremely tough and excellent stability to extend its service lifeWIDE APPLICATION:Diamond Hole Drill Bit Setis suitable for glass, tiles, stone, wood, granite, ceramic and porcelainRUSTLESS, CUTS QUICKLY:Nickel-plated with a diamond dust coating offers superior performance and cutting strength. Extended service life. These diamond drill bits are excellent for making a clean and accurate hole.SHARP & SMOOTH CUT:High quality, good performance, long life - Excellent for making a clean and accurate hole. All the bits are processed for a smooth and exact finishAPPLICATION:Drill Glass, Tile Bottles, Blocks Jars, Fiberglass Porcelain Tile Ceramic, Slate Mable, Granite Light Stone. Excellent for making them clean and accurate hole on glass and tile.TIPS:Can be used with a standard electric drill (not included), Always use lubrication (water), otherwise the diamond core drill will burn. Warnings: Not for use on Concrete or for depths beyond about 1/2"; Water is required for lubrication when drilling.SPEED KILLS:Reduced drill speeds, low drill pressure and increased use of water lubrication will extend drill bit life considerablySpecifications:Material: steelSize Available: 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm, 14mm, 15mm, 16mm, 18mm, 20mm, 22mm, 25mm, 26mm, 28mm, 30mm, 40mmApplicable Industry: Suitable for Stone, Tiles, Ceramics, Glass and Granite, etc Processing.Package Included: 1 pcs x Diamond Hole Drill Bit Note: Please be sure to add water to cool when using it.