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:
Feb. 26, 1980
Filed:
Mar. 28, 1978
Nippon Steel Corporation, Tokyo, JP;
Nippon Steel Bolten Company Ltd., Fukuoka, JP;
Abstract
A screw-bolt having crest-cut-off threads with their heights progressively decreased to not more than 3/4 times the basic height in the screwing up direction at a gradient ranging from 60/100 to 3/100 over that of the axial length of the threaded part of the bolt which is located between the unthreaded part and the complete thread upon setting up engagement with a nut therefor to allow a fraction of 0.1 to 0.2 unengaged with the nut, whereby the fatigue strength is increased in terms of the endurance limit from 6 kg/mm.sup.2 for the prior art bolt and nut to more than 11 kg/mm.sup.2 independently of whether SCM 14 or SNCM 5 steel is used in making the bolt and nut.