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:
Jun. 02, 2026

Filed:

Mar. 16, 2021
Applicant:

Ejot SE & Co. KG, Bad Berleburg, DE;

Inventors:

Ralph J. Hellmig, Bad Laasphe, DE;

Michael Achenbach, Breidenbach, DE;

Fabian Simonsen, Erfurt, DE;

Assignee:

EJOT SE & CO., KG, Bad Berleburg, DE;

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C21D 1/78 (2006.01); C21D 1/20 (2006.01); C21D 9/00 (2006.01);
U.S. Cl.
CPC ...
C21D 1/785 (2013.01); C21D 1/20 (2013.01); C21D 9/0093 (2013.01); C21D 2211/001 (2013.01); C21D 2211/002 (2013.01); C21D 2211/008 (2013.01);
Abstract

The invention relates to a method for producing a screw, having the following steps: (a) rolling a screw wire made of low-alloy carbon steel to produce screw () having a thread; (b) heating the entire screw () to an austenitizing temperature under a carbon atmosphere and/or nitrogen atmosphere and maintaining the temperature; (c) quenching the entire screw () to a bainitizing temperature and maintaining the bainitizing temperature until the screw has a bainitic structure over its cross-section. The invention is characterized in that the screw () is subsequently hardened locally at its tip (), by the tip () being heated to an austenitizing temperature and the screw () being subsequently quenched to a temperature below the martensite starting temperature (MS).


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