The following uses for iron are gathered from a number of sources as well as from anecdotal comments. I would be delighted to receive corrections as well as additional referenced uses.
- pig iron is an alloy containing about 3% carbon with varying amounts of S, Si, Mn, and P. It is hard, brittle, fairly fusible, and is used to produce other alloys, including steel
- wrought iron contains a few tenths of a percent of carbon, is tough, malleable, less fusible, and has usually a "fibrous" structure
- carbon steel is an alloy of iron with carbon, with small amounts of Mn, S, P, and Si
- alloy steels are carbon steels with other additives such as nickel, chromium, vanadium, etc
- iron is the cheapest and most abundant, useful, and important of all metals