brown fused alumina FEPA P grit, for making premium quality jumbo roll,sanding ... heat treatment grain is ceramically bonded with a red iron oxide, this processing can obviously improve the surface area ... , 9.0 Mohs scaleMagnetic Material 0.0076% Grit Size Available (P):12, 16, 20, 24, 30, 36, 40, 50, ... 80, 100, 120, 150, 180, 220 Microgrit Sizes Available (P):240, 280, 320, 360, 400, 500, 600 Grain Size ...