Blast furnaces, the heart of every steel mill, play a special role in the photographs of industrial structures shot by the artist couple Bernd and Hilla Becher. Without a protective covering, a branching of pipes and lines emerges, which makes the functionality of the constructions seem more enigmatic than understandable. With the help of a standardized photographic procedure and a particular viewpoint, the artists isolate the objects from their confusing surroundings and thus make them readable and comparable. Compiled in so-called “typologies,” not only the functional commonalities of these industrial giants can be grasped, but also formal differences and structural or country-specific features. The Freunde acquired the typology of the blast furnace heads shot in Germany and Belgium, while those from the steel regions of North America were gifted by the artists to the Freunde.