Karmansbo iron Works was an iron bar manufacturer, one of the biggest in the region. At the turn of the century 1900 production reached its peak and 75 workers produced approx. 5.000 tones per annum.
With this special refining method, the Lancashire process, a very high quality low carbon iron was achieved. Because of its extremely low phosphorus and sulphur contents most of it was exported to England (Sheffield) and used as raw material for the tool and steel manufacturing. The forge was shut down and the production of the famous Lancashire iron ceased for ever in 1958.

The Karmansbo iron Works Museum is owned by the municipality of Skinnskatteberg. It is also part of the Echo Museum Bergslagen.

The Karmansbo Bruksmiljö Association, formed in 1993, is responsible for preserving the inside as well as the outdoor environment including guiding and other arrangements. All such work is done on a voluntary basis.