The further development of metalworking skills around Argentomagus during the Gallo-Roman era was due essentially to the proliferation of easily-exploitable, surface iron-ore deposits and a plentiful supply of charcoal furnished by the vast local forests.

More than a hundred smelting workshops have been discovered within a 20 km radius of Argentomagus.

The metal thus obtained would have been beaten at temperature and made into ingots before being transported to the forges which fabricated finished articles such as tools and arms.

The site of the Argentomagus arms factory with its Notitia Dignitatum trademark has yet to be found.