... .Applications:GC-GPA can be used in refractory, ceramic and abrasive area, such as making vitrified bonded grinding wheels, ... 120, 150, 180, 220.Microgrit Sizes Available:F240, 280, 320, 360, 400, 500, 600, 800, 1000, 1200.JIS240,280 ... ,320,360,400,500,600,700,800,1000,1200,1500, ... 2006 or ISO 8486-1. Green Silicon Carbide / GC-GPA for vitrified bonded grinding wheel