Iron has a lot of carbon in it, which makes it crack very easily. If some carbon is removed, iron becomes very strong steel.
This steel is used to make tiny paper clips to skyscrapers. Steel is recyclable and can be used over and over again. Steel has become an important material, as it is the key ingredient for making cars, screws, nails, nuts and bolts, it is also used for making huge cranes and for all the construction purposes. Steel girders form the skeleton of new buildings.
Below Steel info from Wikipedia (Read More):-
Steel is an alloy consisting mostly of iron, with a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most cost-effective alloying material for iron, but various other alloying elements are used such as manganese, chromium, vanadium, and tungsten.[1] Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another. Varying the amount of alloying elements and form of their presence in the steel (solute elements, precipitated phase) controls qualities such as the hardness, ductility, and tensile strength of the resulting steel. Steel with increased carbon content can be made harder and stronger than iron, but is also more brittle.
http://en.wikipedia.org/wiki/Steel
