3U vitrified diamond wheels are harder than both resin and metal bonded wheels, for the use in automated equipment and systems, which both resin and metal bonded wheels will flot suffice. These highly demanded bonded wheels must be durable with extended life and be self-truing and self-dressing in order to sustain maximum performance over long periods of heavy use. Vitrified-bond technolog is today's answer. A vitrified bond is actually a ceramic bond. It is extremely hard, yet free cutting, and combines the better characteristics of both resin and metal bonds. It provides a longer tool life, effective grinding, and high productivity, which is desperately sought after to provide maximun performance with minimum maintenance.