THE BALLS are made from pure Silicon Nitride material with extreme high density from uniform compaction (3.25 g/cm3). The micro-structural development of this material during manufacture is second to none. These high precision Grade 5, SI3N4 pure ceramic balls are 5/1,000,000″ from exactly round in sphericity. They are 60% lighter in weight, and 7 times harder than steel. Friction is reduced to near zero.
