Eisenwerke Oberdonau was a large steel

Steel

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 and iron

Iron

Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

 producing company, a holding of several steel works in southern Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 and Austria

Austria

Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

. Created after the Anschluss

Anschluss

The Anschluss , also known as the ', was the occupation and annexation of Austria into Nazi Germany in 1938....

 of Austria, it formed the part of the so-called Reichswerke Hermann Göring AG

Reichswerke Hermann Göring

Reichswerke Hermann Göring was an industrial conglomerate of Nazi Germany. It was established in July 1937 to extract and process domestic iron ores from Salzgitter that were deemed uneconomical by the privately held steel mills...

 cartel, the main supplier of steel and iron for the German war industry during the World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. It is also argued that it was the largest steel mill complex in Europe at that timehttp://www.geheimprojekte.at/t_linz2.html.

The main steel factory in Linz

Linz

Linz is the third-largest city of Austria and capital of the state of Upper Austria . It is located in the north centre of Austria, approximately south of the Czech border, on both sides of the river Danube. The population of the city is , and that of the Greater Linz conurbation is about...

http://www.geheimprojekte.at/t_linz.html supplied its products to the nearby factories of tank hulls and turrets at Sankt Valentin

Sankt Valentin

Sankt Valentin is a town in the district of Amstetten in Lower Austria in Austria....

 (so-called Nibelungenwerk)http://www.geheimprojekte.at/t_valent.html. Throughout the war, the company also ran two sub-camps of the Mauthausen-Gusen concentration camp

Mauthausen-Gusen concentration camp

Mauthausen Concentration Camp grew to become a large group of Nazi concentration camps that was built around the villages of Mauthausen and Gusen in Upper Austria, roughly east of the city of Linz.Initially a single camp at Mauthausen, it expanded over time and by the summer of 1940, the...

 where it benefited from the slave labour of inmates held there.