one end of the spectrum is cast iron or pig iron (so named because when it was first made it would set in a series of channels and moulds resembling a litter of piglets being nursed by their mother). This is a brittle metal with about 3–4 per cent carbon. At the other end is wrought iron, soft enough to be beaten with a hammer and very pure, with infinitesimally small quantities of carbon. In the middle is steel, which typically has less than 2 per cent carbon (and usually, in the case of most mild steels, such as those which once came from the mills at Azovstal, a fair bit less; well below 1
...more
