Outokumpu Oyj is a group of international companies headquartered in Helsinki, Finland, with 10,600 employees in more than 30 countries.

[3] From 1988 to 2001 Outokumpu and the Swedish company Boliden participated in a cartel for copper tubing in the European market.

The new company named AvestaPolarit, headquartered in Stockholm, was jointly owned by Outokumpu and the Corus Group of Swedish institutional investors.

On 31 March 2008, the cold rolling mill in Sheffield was closed in a company-wide 10% fixed cost reduction plan.

[9] On 31 January 2012, Outokumpu announced it would buy Inoxum, the stainless steel division of German ThyssenKrupp, for 2.7 billion euros.

In total Outokumpu recorded a non-recurring capital gain of EUR 389 million (net of taxes and debt repayment) for the sale of the entire 60% share in SKS.

Kemi mine in Keminmaa near Tornio provides chromite, the raw material for chrome, needed to make stainless steel.

[21] After the Avesta Sheffield acquisition, Outokumpu owned the Sheffield facility in the UK includes a melt shop, continuous casting, a bar finishing facility and rod mill which are part of Outokumpu's Long Products business, also a stocking, processing and distribution center.

[22] Outokumpu's UK acquisitions derived from the works created in 1950 as a joint venture between Firth Vickers (see Firth and Vickers) and Samuel Fox and Company for cold rolling stainless steel, established at Shepcote Lane, Sheffield, originally manufactured under the Staybrite brand.

In 2005 the cold rolling and finishing units, Coil Products Sheffield on Shepcote Lane were closed, with the loss of over 600 jobs.

In 2023, Outokumpu divested its Long Products business, including the melting, rod and bar operations in Sheffield, UK, to Marcegaglia.

The Krefeld mill with 100 years of experience in stainless steel production, closed its melt shop in December 2012 and re-focused on cold rolling and R&D.

The nearby Benrath cold rolling mill in Düsseldorf was relocated and joined with Krefeld operations, to make a range of grades, dimensions and surface finishes.

The Dahlerbrück cold rolling mill is located in Sauerland producing precision strip and looks back on a 300-year tradition of iron and steelmaking.