Professional Type vacuum brazed (VB) diamond drill bits are professionally produced for wet or dry drilling in all types of ceramic, porcelain, tile, granite, marble, sandstone and other materials hard. Thanks to VB technology, the diamond drill bits can drill dry or wet on hard porcelain and stone with greater efficiency and longer life.< /p> Diamond drill bits with M14 thread connection can be used directly on the angle grinder. Easy operation, applied for DRY and WET drilling, can work in all conditions. The perfect tools are at your fingertips. diamond cutter allows you to drill the necessary holes for water inlets, drains, light points... diamond drill bit can dry drill dozens holes in HARD PORCELAIN, much longer service life than galvanized (almost 10 times). You can drill many more holes in the wet. To make the diamond drill bits last longer, please follow the correct instructions of the method of use.