... in counter tops. -Top of the line core bits for various types of stone Electro-plated diamond core ... various types of stone(1). Diameter: from Ø3mm to Ø127mm(2). Shank/Top: Round, Trigonal, Hex (3). Diamond grit ... tile, glass, fiberglass, quartz, bricks, and a variety of other materials. (7). It gives excellent clean and fast cutting ... and use with or without center pin. Set of diamond core drill bit