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:
May. 18, 1999
Filed:
Jun. 21, 1996
Applicant:
Inventors:
Assignee:
Sumitomo Electric Industries, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B21F / ;
U.S. Cl.
CPC ...
148333 ; 420105 ; 428544 ; 148663 ;
Abstract
A high-toughness, quenched, oil-tempered wire for springs which is less likely to suffer a permanent set and is high in strength and toughness. The wire is made of a steel containing predetermined amounts of C, Si, Mn, Al and Ti, to which are selectively added predetermined amounts of V, Mo, W and Nb. After quenching and tempering, the content of retained austenite is 1-5 vol. %, and/or the number of carbides having a diameter of 0.05 .mu.m or more is 5 or less per .mu.m.sup.2 as viewed on a transmission electron microscope image.