Sutton Tools Blue Ceram Diamond Core Bits are the professional’s choice tile drill. They feature diamond segment technology, enabling the bit to be dressed for optimal performance and long life. Suits non-hammer action portable power drills. For drilling porcelain, monocottura, marble, glazed, terracotta, sandstone & standard ceramic tiles. Cutting speed with water <3000 RPM *Blue Ceram diamond core bits drill oversize to allow drilling and fixing into material below the surface without chipping the tile.