NEW YORK — The U.S. Patent and Trademark Office will reissue ArcelorMittal SA’s Usibor patent concerning boron steel sheet with an aluminum-based coating.

The move confirms that ArcelorMittal’s U.S. patent 6,296,805 applies to cold-rolled steel for hot stamping and is not limited to hot-rolled steel.

The Luxembourg-based steelmaker previously argued that AK Steel Corp., Severstal Dearborn Inc. and Wheeling-Nisshin Inc. had infringed upon its Usibor patent, but the defendants said their products underwent a cold-rolled process prior to coating and thermal treatment, meaning ArcelorMittal’s patent did not apply (amm.com, Dec. 3). ArcelorMittal had argued that its patent applied to both cold-rolled and hot-rolled steel.

The U.S. Patent and Trademark Office’s decision "is in agreement with ArcelorMittal’s position that the Usibor patent applies notably to cold-rolled steel for hot stamping," a spokeswoman said in a statement. "ArcelorMittal is pleased with the decision confirming its patent rights for this innovative technology and will continue to vigorously enforce and defend its patent rights against any potential infringement."

AK Steel and Wheeling-Nisshin declined to comment. Severstal could not be reached for comment.