AK Steel Prevails Again in Patent Infringement Litigation with ArcelorMittal

 AK Steel Prevails Again in Patent Infringement Litigation with ArcelorMittal

PR Newswire

WEST CHESTER, Ohio, Oct. 29, 2013

WEST CHESTER, Ohio, Oct.29, 2013 /PRNewswire/ --AK Steel (NYSE: AKS) said
today that the United States District Court for the District of Delaware again
confirmed that the company's ULTRALUME® advanced high-strength steel product
does not infringe upon an ArcelorMittal patent. The Court granted summary
judgment in favor of AK Steel on October 25, 2013.

The Court further concluded that ArcelorMittal's patent was invalid due to
ArcelorMittal's deliberate violation of a statutory prohibition on broadening
a patent through reissue more than two years from the grant of the initial
patent.

AK Steel's ULTRALUME® advanced high-strength steel helps automakers design
lighter, more fuel-efficient vehicles without sacrificing occupant safety.
The product has been accepted for use by numerous automotive original
equipment manufacturers, and is used for hot-stamped, press-hardened
applications.

AK Steel
AK Steel produces flat-rolled carbon, stainless and electrical steels,
primarily for automotive, infrastructure and manufacturing, construction and
electrical power generation and distribution markets. The company employs
about 6,100 men and women in Middletown, Mansfield, Coshocton and Zanesville,
Ohio; Butler, Pennsylvania; Ashland, Kentucky; Rockport, Indiana; and its
corporate headquarters in West Chester, Ohio. Additional information about AK
Steel is available on the company's web site at www.aksteel.com.

AK Tube LLC, a wholly-owned subsidiary of AK Steel, employs about 300 men and
women in plants in Walbridge, Ohio and Columbus, Indiana. AK Tube produces
carbon and stainless electric resistance welded (ERW) tubular steel products
for truck, automotive and other markets. Additional information about AK Tube
LLC is available on its web site at www.aktube.com.

AK Coal Resources, Inc., another wholly-owned subsidiary of AK Steel, produces
metallurgical coal from reserves in Somerset County, Pennsylvania. AK Steel
also owns 49.9% of Magnetation LLC, a joint venture headquartered in Grand
Rapids, Minnesota, which produces iron ore concentrate from previously mined
ore reserves.

SOURCE AK Steel

Website: http://www.aksteel.com
Contact: Media - Michael P. Wallner, General Manager, Communications and PR
(513) 425-2688; Investors - Roger K. Newport, Vice President, Finance and
Chief Financial Officer (513) 425-5270