Professional Type Vacuum Brazed (VB) diamond drill bits are professionally manufactured for wet or dry drilling in all kinds of ceramics, porcelain, tiles, granite, marble, stoneware and other hard materials. / p> With VB technology, diamond drill bits can drill dry or wet on hard porcelain and stone with higher efficiency and longer lifespan. Diamond drill bits with M14 thread connection can be used directly on the angle grinder. Easy operation, applicable for DRY and WET drilling, works in all conditions. The perfect tools are at your disposal. With the diamond drill bit you can drill the necessary holes for water inlets, drains, light points, etc. Drill bits With diamond you can drill dozens of holes dry in HARD PORCELAIN, much longer lifespan than galvanized (almost ten times). You can drill many more holes in wet conditions. To extend the life of the diamond core bits, please follow the correct instructions for use.