The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 05, 1995
Filed:
Dec. 09, 1993
Kiyoshi Hirakawa, Kanagawa, JP;
Norifumi Ikeda, Kanagawa, JP;
NSK Ltd., Tokyo, JP;
Abstract
A rolling part steel with which the strength of a rolling part of a cold-worked bearing is improved compared with that of a conventional turned part by controlling the length and number of sulfide inclusions in the steel to an optimal range, when a rolling part steel is prepared so that the maximum length of sulfide inclusions in the steel is 100 .mu.m or less and that a number of sulfide inclusions whose lengths exceed 40 .mu.m is 50 or less per unit area (160 mm.sup.2) , the roughness of its bore surface is improved to have a greater strength. As a result, for example, a thus formed raceway ring has a longer life against fatigue-induced cracks than a turned raceway ring.