silicon nitride ball

59% lighter than steel ball, which means less centrifugal force and less wear on the groove during high speed and acceleration.44% larger elastic modulus, which means less deformation under load.harder with rockwell hardness as 78.smaller friction coefficient.only 1/4 coefficient of thermal expansion of steel, can endure sharp fluctuation of temperature.superior surface finish can be achieved, Ra could be 4 6 nm.can endure high temperature with high hardness and strength up to 1050 °C.never rust, can roll without lubrication.more corrosion resistance than steel.free of metal contamination.non-magnetic.electric isolationno adhesive-wear.