Features Designed to drill the hardest porcelain, ceramic and natural stone (granite, marble, slate and limestone) tile 5/8"-11 threaded attachment fits most angle grinders For wet or dry use Made in Italy Details Mondrillo Diamond Core Bits re equipped with high quality diamond construction ensuring the Bit will quickly dry drill many holes (40 - 60) in the hardest porcelain, ceramic and natural stone. Diamond drill bit works best at 11,000 RPM. The average drill time is 20 seconds per hole!
