1.Material:Chrome Steel, 2.High quality&Fast Delivery 3.ISO9001:2000,ISO/TS16949 4.OEM manufacturer Specification:1.Bore diameter: from 12mm to 140mm:2.Outer diameter: from 47mm to 300mm:3.Material:bearing steel/chrome steel--China,(AISI)52100--American,(Din)100Cr6--Germany4.Certificates:ISO9001:2008,ISO/TS169495.Feilds Used in: Motorcycle, Motor, Pump, Fan, Air conditioner, Microwave Oven , ...