Ironworking in Roman Britain
A variety of metals was mined and used by the Romans, including copper, gold, silver, lead and iron. Ironworking was widespread in Britain by the later Iron Age. In fact, iron was listed as a British export by the Greek author Strabo shortly before the Roman invasion. With the incorporation of Britain into the Empire large-scale production was achieved.
Ores were available in most parts of the country and iron became the cheapest metal, and was used for a diverse range of fittings and objects. Most blacksmiths probably bought their raw material from smelters, in the form of ingots or rods. Another source was scrap metal; broken or worn iron objects would be taken to the smith for re-forging.
Unlike other metals, iron was not cast in the Roman period. Instead, the blacksmith forged it in a semi-solid, red-hot state using hammer and tongs. Thin iron sheet was joined with rivets, but the normal joining technique was welding at white heat. Various hardening techniques were known, and steeled cutting edges were sometimes welded to tools and weapons. Few of these techniques were new, and it was not the case that a poor Iron Age technology was replaced by a superior Roman one. Rather, existing skills were adapted to changed circumstance, notably a new, highly-organised trading network.