Item No.: CF3~CF16Ball: Gcr15 Steel, heat treated, HRC56 min; Precision ground polished hard chromium plated Body: Carbon steel, Zinc plated, chromate treated Sliding contact surfaces: Steel/SteelPhone: +86-592-580 8851 / +86-592-580 7618Email: sales@ldk-bearing.com ; benjamin@ldk-bearings.com