1. Material: Silicon nitride is a chemical compound of the elements silicon and nitrogen, with the formula Si3N4. They provide very good mechanical/thoughness properties and corrosion resistance. They are auto lubricant materials and good electric insulators. They have excellent resistance to thermal shocks.It is the most thermodynamically stable of the silicon nitrides. Hence, Si3N4 is the most commercially important of the silicon nitrides^[2] and is generally understood as what is being referred to where the term "silicon nitride" is used.

2. Size: 1 mm-50.8mm, or as per clients' requirements 

3. Color: black

4. Feature: Ceramic balls are self-lubricating, so it's both OK to use grease or not use. It is of low density, medium elasticity, small thermal expansion, high hardness, high temperature resistance, good corrosion resistance, magnetism free. Ceramic ball bearings using silicon nitride ceramic balls as rolling element, can obviously improve bearings' using life, and extremely expande bearings' application field. 

5. Application: High precision and high rotating speed machine tool, automobile, racing car, metro, power generator, aerospace generator, petrol and chemical machine, metallurgy machine. 

6. Packing: Industrial packing, or as clients' requirement.