1) Crude iron, which has a 5% -4% carbon, and varying amounts of contaminants such as sulfur, silicon and phosphorus and its importance is only an intermediate step on the way due to iron ore to iron and steel.
2) Pig iron, including 5/3% -2% carbon and small amount of magnesium. Impurities such as sulfur and phosphorus in pig iron that negatively affect the properties of the cast iron are reduced to an acceptable level. The melting point of Pig iron is between 1470-1420 k that it is lower than both the original composition and then heating it to the molten product also makes carbon and iron.Cast iron used, even white cast iron heat is breaking objects.
3) Carbon steel, includes 1/5% – 0/5% carbon and small amounts of manganese, sulfur, phosphorus and silicon.
4) Soft iron (iron), has less than 0/5% carbon, and the product is strong and malleable, but not fusible as pig iron. Containing small amounts of carbon (a few tenths of a percent). If you have a sharp edge, it quickly loses its sharpness.
5) Alloy steels contain varying amounts of carbon, as well as other metals such as chromium, vanadium, molybdenum, nickel, tungsten and …is.