2Pcs 8mm Diamond Drill Bits Core Bits with M14 Thread for Dry Drilling Porcelain Tile Granite Marble <p>Vacuum brazed (VB) diamond drill bits are professionally produced for wet or dry drilling in all types of ceramic, porcelain, tile, granite, marble, stoneware and other hard materials. Thanks to VB technology, diamond drill bits can drill dry or wet on hard porcelain and stone with higher efficiency and longer life. 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 hand. Diamond cutter allows drilling the necessary holes for water inlets, drains, light points... Diamond drill bit can dry drill dozens of holes in HARD PORCELAIN, much longer life than galvanized (almost 10 times). You can drill much more holes in the wet. To make the diamond drill bits last longer, please follow the correct instructions for use.</p> Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.