Nippon Seiko Kabushiki Kaisha

Yasuo Utsumi

Yoichi Matsumoto

Kousuke Nonaka

A rolling member used as an outer race, inner race, a ball or roller of a bearing contains a metal flow in the structure formed by plastic working (fold forging). The angle of metal flow determined by a tangent line of the metal flow and the axis of rotation of the rolling member is 10.degree. or larger to improve the service line against rolling fatigue.

Rolling member

A rolling bearing in which a bearing ring and/or a rolling element comprises an alloy steel wherein the hardness of a surface layer over a thickness corresponding to greater than 2% of a mean diameter of a rolling element is equal to or greater than 60 HRC and the hardness at least of the raceway surface or the rolling contact surface is equal to or greater than 64 and equal to or less than 69 HRC, and carbides of equal to or greater than 6 .mu.m converted as the diameter of a circle are not contained in a range from the raceway surface of the rolling contact surface as far as the depth corresponding to 2% of the mean diameter of the rolling element.

Growing community of inventors

Fujisawa, Japan

Yasuo Utsumi