10pc Diamond Hole Saw Drill Bit masonry drilling 6-30mm Holesaw Tile Ceramic Glass Marble Drilling Bits Hole Opener Cutter --This diamond coated core drill bit removes a complete circle from glass, tiles, marble, granite, ceramic or other materials and only needs water for lubrication. --Always use lubrication (water), otherwise the diamond core drill will burn. --Can be used with a standard electric drill. --Start your hole diagonally, make a round trace and then hold drill straight.