• Highlight: The MK Diamond MK-190 5/16-inch wet diamond core bit drills clean, chip-free holes through porcelain, granite, marble, and ceramic tile using sintered diamond matrix and a 3/8-inch arbor.
• Best For: Tile setters, plumbers, and stone fabricators drilling small-diameter holes for faucet and fixture penetrations in finished porcelain and natural-stone tile.
• Expert Note: Start the MK-190 at a shallow angle to score the glaze, then bring the bit upright once the diamond has bitten - this stops walking on slick porcelain better than any guide jig.
