In/External Ring Carbon steel, Chrome steel, Stainless steel Ball Carbon steel, Chrome steel, stainless steel Retainer PA6, Steel strip, Brass strip Heat Treatment Carbonnitruration, Quenching,Hardening Antirust Treatment Zinc-plating, Nickle-plating, Chrome-plating Race Finishing Grinding, Super-grinding Plastic Covering PA, POM Package: wood salver/steel salver Delivery:Air ( Shanghai)/Sea (Main port :Shanghai Ningbo) Material, Tolerance, Lubrication, Technical parameter