A very great number of arrowheads and arrows of catapult was excavated from "Le Puy d'Issolud" , probable site of the fight of Uxellodunum, given by Caesar, in 51 B.C. Till now, only a typological study was devoted to them. Here are gathered the first data about microstructure and local analysis (OM, SEM, EDXS, XR, microhardness HV) of weapons selected for their archaeological value. In the same time were made: examination of metal (Fe-C alloys, between pure enough iron and quasi-eutectoid steel), of corrosion layers and of the two types of residual slags, produced during direct reduction or forging. This contributes to reach a better approach of treatments and forging practice, during the Roman period.