Features: 1) Materials: silicon nitride 2) Usage: for bearings, inspection, and other rolling conditions 3) Exported to Japan, Korea, North America and Europe 4) Capacity: 3,000,000pcs/month for 5/32 " silicon nitride balls 5) Diameter: 1/64" ~ 5/4" 6) Precision: G3 ~ G20 Specifications: 1) 60% lighter than steel 2) Has elastic modulus 50% larger than that of steel 3) Lower friction coefficient, rolls more freely 4) Coefficient of thermal expansion is only one third of that of steel 5) Superior surface finish 6) High-temperature hardness is twice than that of steel 7) Never rust, and can roll without oil or grease 8) Better corrosion resistant than steel