Abstract
In this paper, we theoretically analyzed the non-repetitive run-out (NRRO) of rolling bearings used in machine tools caused by form errors of inner and outer races and rolling balls. It was recommended to use higher grade balls in order to reduce NRRO of rolling bearing used in machine tools. Diameter difference of balls in a bearing and even con-ponents of form error of balls are important factors to reduce NRRO.
