Ferrous, in the chemical science realm, indicates a bivalent iron compound (+2 oxidation state) (as opposed to ferric, which indicates a trivalent iron compound (+3 oxidation state)). Outside of chemical science, ferrous is an adjective used to indicate the presence of iron. Ferrous metals include steel and pig iron (which contain a few percent of carbon) and alloys of iron with other metals (such as stainless steel.) The term non-ferrous is used to indicate metals other than iron and alloys tha… (More on Ferrous)