Tenryu Super Diamond, Center Cup Wheel TSD-105C. 4 Dia., 7/8 Arbor. FAST GRINDING of cast iron, ductile iron, steel, granite, marble and other natural stones, ceramic materials, solid-surface materials, fiber reinforced plastics, brick and a variety of masonry products. Until now, standard diamond grinding wheels were the only choice for stone workers. They were expensive and wore quickly when used heavily. The TSD (TENRYU Super Diamond) removes material very rapidly and will last longer than conventional diamond tooling. Curved outer edge makes it easier to grind the insides of holes and curved shaped surfaces.