Enduro Bearings 61903 LLU/LLB CN A5 - ABEC 5 - 17x30x7

Enduro Bearings 61903 LLU/LLB CN A5 - ABEC 5 - 17x30x7

Grade 5 Chromium Steel Balls

High precision balls are within 5/1,000,000″ round. These are military level specification, used for precision equipment. R-64 hardness, of the highest grade.

52100 High Carbon Chromium Alloy Races

Enduro Bearings uses highest quality 52100 High Carbon Chromium Steel Alloy race material from Japan. There are many suppliers of 52100 material, but they do not all necessarily provide the same quality material. The material for Enduro steel races starts with and extremely-pure, vacuum de-gassed chromium steel alloy that is then hardened to Rockwell HRC 64 by multiple rounds of heat and cryogenic treatment.