3pcs vacuum welded drill bits M14 thread diameter Diameter 6,8,10mm, total length 60mm, M14 thread Dry or wet drilling of tiles, stone, marble, granite, ceramics Vacuum brazing technology offers a much longer service life than galvanized Less chipping; Minimize breakage; Less heat generation; Best surface quality Product Description Wax for cooling The inside of the drill is filled with dense cooling wax to cool diamond drill bits and extend the life of drill bits. Application Drilling porcelain, tile, marble, brick, stone, granite, masonry and all similar materials that are not recommended for the material behind the tile. Usage When you are building or remodeling a bathroom or kitchen, for example installing a shower or installing a faucet and handles in the bathroom, you need to drill holes through the porcelain tiles without cracking them. So with our diamond drill bit you can drill these holes very precisely.