Hans Lenze’s career till 1947

Hans Lenze is born on 9 March 1890 in Dortmund as the son of the teacher Caspar Lenze and his wife Berta, maiden name Walch. After his normal schooling, he attends the city’s trade school, completes his military service, begins an apprenticeship in commerce in 1908 and then becomes self-employed for the first time, as a cork trader in Spain. During the First World War (1914-1918) he fights in France.

On leave from the front in 1917, he marries Clara Leder, and soon three children are born (1918 Wilfried, 1919 Lore and 1921 Elisabeth). After the end of the war in 1918, Lenze takes on positions in the management of various companies.

When Mannesmann-Röhrenwerke moves its export activities into a new company, Mannesmann-Export GmbH (known as Mannex), Hans Lenze is appointed as its first managing director. He has thus become the head of exports for a coal and steel conglomerate with 50,000 employees.


Production at Mannesmann is heavily involved in rearmament and the war economy. It “Arianizes” rival companies and uses forced labor. The concern’s trading company, managed by Hans Lenze, plays a subordinate role in this by setting up branches in the areas occupied by the German army (Wehrmacht). This expansion ends when the German troops are pushed back in the course of the Second World War. Although Hans Lenze is not involved in the concern’s war-related manufacturing, he later comes to a self-critical assessment of his position. In 1956 he writes a letter to his employees that is remarkably open:

“I, too, am one of those people who focused only on their work and cared little for their fellow human beings.” He says he “did not see the direct path leading from the Olympic fire in Berlin to the incinerators in Buchenwald”.

Hans Lenze has taken this metaphor from a lecture by the actor Viktor de Kowa, with his permission. He links it with a promise: “never again to look without interest at what happens to my fellow human beings.”

In 1939, Mannex changes its name to Stahlkontor to hide its connection with Mannesmann. The company moves from Düsseldorf to Hamelin in 1943 because of the bombing raids. At the end of the war in 1945, Stahlkontor in Hameln has a well-stocked warehouse from which it sells valves, rolling bearings, tools and other material to companies in the local area.

Hans Lenze sees his opportunity: “I had the idea of trying to do something that not many other people had tried after the lost war, namely to seek my fortune in trading.” In May 1947 he bought Stahlkontor with around 30 employees from Mannesmann and on 5 November he founded Stahlkontor Weser GmbH, Hameln.

To finance the deal, Clara Lenze sells her parents’ house in Düsseldorf, and that is how it all begins.