Planar Grinding Stones - BuehlerPlanar Grinding Stones are multi-use abrasive discs designed for the PlanarMet 300. They provide high material removal rates and consistent scratch patterns.internal grinding s c3 bcper stones,Grinding Wheels & Honing Stones | Wissota Skate SharpenersPurchase grinding wheels and honing stones for your Wissota 911 Skate . Choose between 60, 80, and 100 Grit grinding wheel stones. . 1 Review(s). $30.00.