1.carbon steel ball retainer 2.Hardness:HRC58-62 3.could be ... in bicycle,bearings 4.1/4" x 6/7/9/11 size ball retainers for bicycle parts,bearing cages,copper,nickle ... ):Steel Ball,Ball Retainer,Stainless Steel Ball,Coloured Steel Ball,Carbon Steel Ball,Ball Bearings Registered Address:Weizhuang, Huangji Township, Yuncheng ...