bearing steel ball 7.938mm~~25.4mm bearing steel ball GCR15Specification :Diameter(mm):8.731Grade:G10ball diameter variation:(not over)0.25μmdeviation from spherical from :(not over)0.25μmsurface soughness : (not over)0.025μmlot diameter variation :(not over)0.5μmguages interval:1preferred guages :-9,...-1,0,+1,...+9subguage interval :0.2subguages :-0.4,0.2,0+0.2,+0.4Per 10000 pcs:27.1kgNo.of ...