International audienceMethodological advances linked to the direct dating of iron through carbon 14 have recently opened the way to important discoveries, whether about the use of iron in construction, or again in the organization of networks of distribution of iron products from Proto-history to the Middle Ages. The dating approach developed up until now has been based on the need obey a two-step process: a piece of metal would be sampled with the goal of a detailed observation of the metallic structure in a laboratory setting, which would then allow the researcher to lift samples for dating. However, the precious nature of the works in museum collections encourages us to rethink the protocol and reduce it to one single step with an in sit...