Silicon Nitride Balls

Synthetic sapphire balls are used in applications requiring hardness, lightness, corrosion-resistance and electrical non-conductivity such as bearings, and as wear points in instruments.  Commonly mounted on stems, ruby sapphire balls are also used as probes in coordinate measuring machines, in gauging devices, and in as floats in flowmeters where precise diameter tolerance is important.  Ruby sapphire balls have a coefficient of thermal expansion just 25% that of most metals.  Some sizes are available from stock; others may be manufactured to your specifications.

The most common use for silicon nitride balls is in bearings.  Silicon nitride bearing balls have a coefficient of thermal expansion just 25% if most steel balls, so there is less friction generated in the bearing as heat increases.  The low thermal conductivity of silicon nitride balls reduces the amount of heat absorbed, thus reducing cooling system requirements.  Some sizes are available from stock; others may be manufactured to your specifications.