Sap, right on the mark once again. I did a quick look since I've spent quite a bit of time in this region.
Here's a quick translation describing the "Eberfingischen Bergmünzen" (below), and a small pic I took from a local museum:
During the 30-year war (1618 - 1648), A chief product of the Eberfingen iron smelting plant was the manufacture of cannon balls.
From that time comes the coining of the Bergmünzen of Eberfingen, which are now unusual rarities of copper and brass. These coins provided means of settlement of wages towards purchasing in factory stores.
In mid-18th Century in the Black Forest wood gradually became scarce, so that by 1761 the operation of the steel plant was discontinued -- today only black earth remains on Wutachufer to allude to the former iron production in Eberfingen.
However, if that coin comes from the period of operation, it's in remarkable condition--and probably valuable. Another possibility would be a replica sold to collectors, but that's an unqualified guess.