Steel as a building material in many ways replaced the outdated iron.
Until the 70s of the 19th century, the dominant structural material has been cast, but in its stead came shortly steel. By the beginning of the 20th century, production of iron and steel is almost equal. In this part of the cast iron is processed into steel. The value of iron as the final product has fallen sharply and the value have increased significantly.
Since the 70s of the 19th century to the present day steel is a basic