12PCS/SET M14 Dry Vacuum Brazed Diamond Drill Core Bit Set Drilling Hole Saw Tools For Tile Marble Granite Stone. Dry drilling without water feeding, 6mm-12mm bits with Wax inside helps cooling the bits?? 2. Wide application for drilling tile ceramic granite marble stone. Vacuum Brazed technology provide much longer working life than electroplated ones (Generally 3-5times)?? 4. Less Chipping, Minimizing breakage, less heat generation, Better finish quality?? 5. High diamond exposure rate provides a faster and more aggressive drilling.