5.5mm Diameter Grade 1000 Hardened 52100 Carbon Steel Ball Bearing

General Purpose Grade 1000 Hardened Carbon Steel Ball Bearings: High Quality Graded Hardened Carbon Steel Ball bearings made from Carbon AISI 1010 steel. Hardened to 60-67 Rockwell Scale equivalent to 700-900 HV (Vickers Scale) and are hardened all the way through the ball. These are the same hardened steel balls used to manufacture bearing assemblies and have a high duty and life cycle.