Our stone core bits are aggressive and long-lasting. The soft bonded segments are made for the hardest granites and will core holes in seconds, not minutes. Vacuum brazed diamonds are on the outside of the barrel of our 1 inch - 2 inch bits to prevent the bit from locking up. Arbor is 5/8 - 11 to fit all grinders and polishers. Concut® also manufactures custom core bits for any specifications required.