Ceramic ball Features: Usage: for bearings, inspection, and other rolling conditions Exported to japan, korea, north america and europe Capacity: , , pcs/month for / " silicon nitride balls Diameter: / " ~ / " Precision: g ~ g Specifications: % lighter than steel Elastic modulus % larger than that of steel Lower friction coefficient, rolls more freely Coefficient of thermal expansion is only one third of that of steel Superior surface finish High temperature hardness is twice than that of steel Never rust, and can roll without oil or grease Better corrosion resistant than steel