Diamond hole saws are meant for drilling wall and floor tiles, stone, concrete, marble, and glass. Thanks to the diamond coating on the blade, they hold up well against wear when drilling tough materials. You can guide diamond hole saws with special guides or by using a piece of cardboard with a V-shaped notch cut into it. By placing the blade in the notch, it stays put until the cutting groove forms. NOTE! You gotta use water when cutting! For wall and floor tiles, stone, concrete, marble, and glass. Use water when cutting.