... High speed,Smooth cut. Electro-plated diamond core drill bit (hole saw) :-Fast, clean and efficient way to core holes in counter tops ... as your requirement (6). Used to drill marble, ceramics, porcelain, tile, glass, fiberglass, quartz, bricks, and a variety of other materials. ( ... long life. (8). It is very easy to assemble and use with or without center pin. Electroplated diamond tile drill bit