This certificate evidences and certifies the superiority of pure iron in resisting corrosion over mild steel and wrought iron. This fact is disputed by Chris Topp and Co whose website promotes and markets re-worked scrap wrought iron. The following is a statement taken from that site.
“Pure Iron Chemically pure iron is made for use in the electrical industries for its low hysteresis. It also finds a use in the chemical and shipbuilding industries for sacrificial anodes as it corrodes preferentially to mild steel and hence protects it. Pure iron is claimed by its suppliers to have properties of resistance to corrosion, but its manufacturers make no such claim, and indeed manufacture other steels with corrosion resistance in mind, such as Corten, or Weathering Steel. Pure iron can be forged and forge-welded, as can mild steel but is rather more expensive.”
Interestingly, the site does not provide any evidence in support of these claims and most of the stated “facts” are either untrue, misleading or simply inaccurate. Sacrificial anodes are made from alloys not pure iron.
Pure iron is manufactured primarily for use as the main ingredient in special steels and a small proportion for the pharmaceutical and other industries. We take a tiny proportion of the amount produced to turn it into iron bars and sheet which can be used by artist blacksmiths and restorers as the most appropriate replacement for corroded wrought iron or for new work where forgeability, provenance and aesthetics are a priority.