The Van Leer company established a steel rolling mill ("Walsbedrijven NV") at the IJmuiden site in the late 1930s; a plate mill began production in 1938, followed by a strip and profile mill in 1939. As built it was outdated, using second hand equipment. The mill was built to supply the Van Leer company's own steel needs, and not as an independent commercial concern. In 1941, under the Nazi occupation during World War II, Van Leer's Jewish owner Bernard van Leer was forced to flee the country, and the mill was acquired by KNHS, and integrated into the rest of the IJmuiden site: it became known as "Walserij Oost", remaining in use until 1953, and being replaced by the mills of "Breedband NV".