Iron+and+Steel

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 The cast iron and steel are construction materials very important, both serve to do elements like tubes... The steel is heavier than iron, but just a little, the cost are very similar for both, equally the appearance of the steel is alike than iron, because become from the last. The cast iron can adopt any shape but is weaker than steel in tension. The two materials are very strong. For these reason are used for do structures that are always expose to a big charges, like brigdes and columns. =====