Compared with steel ball, Si3N4 ball has following advantages: 1. 59% lighter than steel ball, which means less centrifugal force and less wear on the groove during high speed and acceleration. 2. 44% larger elastic modulus, which means less deformation under load. 3. Harder with Rockwell hardness as 78. 4. Smaller friction coefficient. 5. Only 1/4 coefficient of thermal expansion of steel, can endure sharp fluctuation of temperature. 6. Superior surface finish can be achieved, Ra could be 4~6 nm. 7. Can endure high temperature with high hardness and strength up to 1050 degrees. 8. Never rust, and can roll without lubrication. 9. More corrosion resistant than steel. 10. Free of metal contamination. 11. Non-magnetic. 12. Electric isolation. 13. No adhesive-wear with metal. 14. Contact angular is very large with molten and nearly no reaction. All above combination makes Si3N4 to be first choice for high-demand bearing ball material and valve ball. Application: Si3N4 ball can be used in all bearings with special requirement: high speed bearing, high precision bearing; vacuum bearing; high/low temperature bearing, non-magnetic bearing, high precision ball screw; Si3N4 ball can also be used as valve ball and metering ball in chemical pump, high-temperature pump, metering pump. Si3N4 ball is generally assembled in bearing for application in high-tech industry such as aerospace, national defense, chemical industry, metallurgical, medical, food, oil plant, electronic etc. Company Feature: stable quality and high consistency with ASTM F2094-03a standard. Size Range: 0.4mm~100mm. Grade: G3~G40. Note: 1) black color as standard, gray color could be supplied upon customer requirement. 2) Plenty of stock. 3) Non-standard size and different gauge could be supplied. Vacuum plastic.