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:
Nov. 07, 2023
Filed:
Jun. 17, 2020
Sumitomo Electric Industries, Ltd., Osaka, JP;
Hiromu Izumida, Osaka, JP;
Tetsuya Nakajima, Osaka, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
A spring steel wire includes a main body made of a steel and having a line shape, and an oxidized layer covering an outer peripheral surface of the main body. The steel constituting the main body contains not less than 0.62 mass % and not more than 0.68 mass % C, not less than 1.6 mass % and not more than 2 mass % Si, not less than 0.2 mass % and not more than 0.5 mass % Mn, not less than 1.7 mass % and not more than 2 mass % Cr, and not less than 0.15 mass % and not more than 0.25 mass % V, with the balance being Fe and unavoidable impurities. A value obtained by dividing a sum of a Si content and a Mn content by a Cr content is not less than 0.9 and not more than 1.4. The steel constituting the main body has a tempered martensite structure.