Item No.: B-GE4C~B-GE30CMaterial:Gc15,ball surface polished,hard chrome plated. Heat treatment: HRC 58-64 Stainless steel 440c are optional. Can custom made per customer’s request.Phone: +86-592-580 8851 / +86-592-580 7618Email: sales@ldk-bearing.com ; benjamin@ldk-bearings.com