3M Vitrified Grinding Wheel 92VH is a vitrified bonded grinding wheel featuring a mix of white aluminum oxide, monocrystalline aluminum and white crushed ceramic grain for conventional generating gear grinding operations.About Vitrified Bonds 3M Vitrified Grinding Wheel 92VH is a conventional grinding wheel with a vitrified bond. Vitrified bonds are manufactured primarily of synthetic, technical glasses referred to as low-temperature bonds. Wheels made with these bonds are insensitive to chemicals and can be stored indefinitely. This particular grinding wheel is targeted for conventional generating gear grinding operations, and features a mix of white aluminum oxide, monocrystalline aluminum and white crushed ceramic grain.