Cast iron
Cast iron is made from pig iron, which is the product of smelting iron ore in a blast furnace. Cast iron can be made directly from the molten pig iron or by re-melting pig iron, often along with substantial quantities of iron, steel, limestone, carbon (coke) and taking various steps to remove undesirable contaminants. Phosphorus and sulfur may be burnt out of the molten iron, but this also burns out the carbon, which must be replaced. Depending on the application, carbon and silicon content are adjusted to the desired levels, which may be anywhere from 2–3.5% and 1–3%, respectively. If desired, other elements are then added to the melt before the final form is produced by casting.
Window shutter hardware
Wrought Iron - literally "hammered" iron. Early on, billets of cast iron were transferred to iron forges. The cast iron billets were heated to near-molten and flattened under a heavy water-powered drop hammer - kind of a see-saw with a couple of hundred pound chunk of iron "hammer" on one end of a heavy wooden beam and a rotating wooden cam acting on the other end to lift and drop the hammer in time with the turning of the water wheel. Valley Forge took its name from a small shop such as this which the British burned, unopposed, on their way to Philadelphia in 1776. Once hammered thinner and longer the billet would be doubled backed on its length, re-heated and re-hammered. This repeated exposure to the oxygen in the fire and the compressing blows of the hammer would burn and drive impurities from the billet. The iron being forged would become increasingly malleable with each heat to which it was subjected. The finest forging iron was multi-layered and nearly pure iron. To the best of my knowledge, there is no new wrought iron being produced today. Well, maybe Japanese Samurai swordsmiths still make their own – but if it's in Home Depot and says "Wrought Iron" it isn't.