Review on 💎 High-quality 6 30mm Diamond Coated Ceramic Marble for Superior Cutting and Polishing by Eric Pavelko

Worked as described, perfect holes in marble tile and cement board with little effort. The hardest part was guiding it [at an angle at first], but once it bites in and you straighten the bit, it only takes a minute. Provided you have adequate cooling and are letting the drill work at its own pace, don't apply much pressure or speed. I made a small "wall" of plumbing putty around the area I was cutting, filled it with water, and added more water as I drilled to keep it clean and cool.