... bicycle,bearings 4.1/4" x 6/7/9/11 size ball retainers for bicycle parts,bearing cages,copper,nickle plated ... )Feature: wear-resisting, excellent surface quality and high hardness.7)Using:1. General industry for automobile, motorcycle, bicycle manufacturing, special bearings & ... 3. High - speed, low noise special bearing 4. Ball valves for liquid and gas ect 7/32" Series steel ball retainer with chrome ...