For centuries, mankind had built with steel, an iron-based alloy doped with other elements to make the molecular structure of the iron stronger. Ferrite, in contrast, is very pure iron threaded with iron nanocrystals which are fantastically strong. First discovered on Earth in AD 1988, it could only be made by the microgram. Centuries later, the Illyrians could produce it by the ton.
Ferrite is expensive to manufacture, and once cast it cannot be malleably re-shaped like ordinary metals, though it can be cut to shape using the right equipment. This limits its scrap value from dead mechs; any ferrite parts you re-use must be cut down to suit their new application. Ferrite's strength makes it essential for structural components of mechs and for machine parts used for a range of applications.
Ferronite is denominated to one of the states not refined during the process of obtaining the Ferrite.
(From Mecha Galaxy Lore)
