APEXX Brazed Sink Drums 5/8-11 Thread. Grit: Coarse. Diameter: 1/2". Diamond Height: 2” (50mm). Thread: 5/8”-11. MAX RPM: 6,500. For use on hand-held angle grinders. Built with our advanced vacuum brazing technology; The diamond grinding surface will always stay straight and never lose its shape; Well balanced; As small as 1/2" in diameter to clean up super tight sink-hole corners; 2" diamond height gives more room for versatile jobs; Available in Coarse, Medium & Fine grits; Material: Engineered Stone, Granite, Marble; Dry or Wet use.