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.

Date of Patent:
Dec. 25, 1979

Filed:

Sep. 21, 1978
Applicant:
Inventors:

George L Joseph, Morgan Hill, CA (US);

Charles A Brolin, Cedar Rapids, IA (US);

Assignee:

FMC Corporation, San Jose, CA (US);

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C21D / ; C21D / ;
U.S. Cl.
CPC ...
148150 ; 148 / ; 148 36 ; 148 39 ; 148152 ; 148154 ;
Abstract

A method of forming a torsion bar wherein steel, preferably an alloy steel of medium carbon content, is formed in the desired size and shape and is through hardened for providing a desired core hardness. The case of the bar is then hardened for transforming austenite in the case into martensite causing the case to expand thereby inducing high compressive stresses near the surface with the compressive stress decreasing radially inward of the surface. The core of the bar is retained below lower transformation temperature for resisting expansion of the case thereby inducing hoop and axial compressive stresses and radial tensile stressed in the case. A torsion bar formed by the method of the present invention is also disclosed.


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