... antiwear 3) use high-speed and low-noise bearing, bicycle, motorcycle, automobile, We have the most ... ballSIZE19.05mm-250mmMaterialsGCr15HardnessHRC58--66ApplicationAuto industry , Wind Power , Slewing bearing , Tower crane,Marine Machinery, Aerospace Industry , Military industry ... 3≤0.25≤0.5GCr15SiMn0.95-1.050.45-0.750.95-1.251.4-1.65 ... 25 high precision durable GCr15 steel ball/bearing steel ball