Goldblatt 10PC 1/4 Diamond Hole Saw Drill Bit Tile Ceramic Concrete Maker Cutter

Faster the RPM, longer the drill bit's working life. Suitable for porcelain, ceramic, granite, marble, masonry, concrete, other types of tile. (Note: NOT for tempered glass, plastic and wood). Diamond Coating: The drill bits are made of high quality diamond by vacuum brazed diamond technology.