Born in Koblenz in 1863, Peter Klöckner had worked in the iron and steel industry for 24 years by the time the company was founded, having previously made a name for himself through business restructuring and investments.

In 1911, a branch was opened in Mannheim to cover the southwest of Germany and to link up with the company's production site in Kneuttingen.

[6] Following the integration of the branches in Troisdorf[7] and Düsseldorf, the group's companies covered the entire range of industrial production in Germany.

The trading company served as an intermediary in the production chain, which, as early as 1912, extended from ore mining to the manufacturing of wires and machines.

During the economic crisis following the end of the First World War, Klöckner & Co compensated for its losses in the steel business by expanding the company's fields of activity.

In the 1920s and 1930s, the trading company established its foreign department and opened its first branches in Europe, as well as in South and North America.

In Hasbergen-Ohrbeck near Osnabrück, the Gestapo set up a labor education camp, which probably held over 2000 prisoners who were forced to work in the nearby Klöckner plants.

[19][20] While continuing to expand its stockholding steel trading in Europe, the group divested activities that were no longer part of its core business.

[26][27] The shares are admitted to trading on the Frankfurt Stock Exchange regulated market with additional post-admission obligations (Prime Standard).

[30] In 2011, Macsteel Service Centers USA and Frefer, Brazil's third-largest steel and metal distributor,[31] became part of the group.

[41] In May 2021, Guido Kerkhoff succeeded Gisbert Rühl as Chairman of the Management Board of Klöckner & Co.[42] Under his leadership, the group's sustainability strategy was further developed, and activities related to green steel were expanded.

[43][44] Klöckner & Co has also focused on selective acquisitions, including Hernandez Stainless, RSC Rostfrei Coilcenter,[45] National Materials of Mexico (NMM),[46] Industrial Manufacturing Services (IMS), and Sol Components in recent years.

Additionally, as part of the portfolio optimization and the implementation of the corporate strategy, the company announced the planned sale of the distribution business in four European countries in December 2023.

In addition, the move offers several operational advantages and is directly related to the existing real estate and personnel capacities.

The company's business is the distribution of steel and metal products, their processing, as well as the acquisition and management of investments of all kinds.

[54] The business activities are managed by the Executive Board and the central departments of the Duisburg Holding and are carried out by the national companies.

In March 2023, the investment company Swoctem, wholly owned by Friedhelm Loh, submitted a voluntary public takeover offer for Klöckner & Co.[56] The aim was to exceed the threshold of 30% without achieving an absolute majority.

As of December 31, 2023, institutional investors held most of Klöckner & Co.'s shares:[58] Swoctem (41.53%), Goldman Sachs (4.99%), Amiral Gestion (3.11%), and Dimensional Holdings (3.01%).

[59] Since 2006, the KCO share has been traded on the regulated market (Prime Standard) of the Frankfurt Stock Exchange and is listed on the SDAX.

[65][66] Klöckner & Co's customers are small and medium-sized companies as well as large international corporations, many of which are mainly in the construction industry and the mechanical and plant engineering sectors.

[67][68] One of its digital applications is the Kloeckner Assistant, which uses artificial intelligence to automatically process incoming price inquiries and orders received by fax or phone.

For 2023, Klöckner & Co received the German Sustainability Award (Deutscher Nachhaltigkeitspreis, DNP) in the Climate Transformation Field category.