1)High precision, strong hardness2)strong antiwear 3) use high-speed and low-noise bearing, bicycle, motorcycle, automobile, We have ... steel ballSIZE19.05mm-250mmMaterialsGCr15HardnessHRC58--66ApplicationAuto industry , Wind Power , Slewing bearing , Tower crane,Marine Machinery, Aerospace Industry , Military industry, ... 0.025≤0.3≤0.25 high precision 52100 bearing chrome steel ball/bearing steel ball