A 6th-8th c. wire-drawing iron plate with silver residue from a Vendel Period workshop in Old Uppsala, Sweden

Metal wire is in modern society manufactured by drawing metal rods through dies with conical holes of decreasing diameters, until the desired thickness is obtained. The history and origin of this technique remains unclear, although it was likely developed from earlier wire-making techniques such as strip-drawing and rolldrawing. Proper wire-drawing was an established technology in Europe during the High Middle Ages, and numerous draw-plates have been found at Scandinavian Viking Age trading centers. Here, we report the technical examination of an iron draw-plate found in Uppsala in central Sweden. The draw-plate was excavated in a Vendel Period fine metals workshop, located immediately next to the royal hall in Old Uppsala, the central building of the royal estate in the 6th -8th c. X-ray and scanning electron microscopy (SEM) analysis of the draw-plate revealed silver particles in the plate's holes, indicating drawing of silver wire. The plate is dated to the 6th - 8th c., which makes it one of the oldest confirmed tools for wire-drawing so far encountered. The presence of this tool in the workshop indicates that some high-quality jewelry in this region was locally produced. Thus, the finding of this draw-plate increases our understanding of Vendel Period jewelry production, and of the social organization of this craft