Why is steel often called the backbone of modern industry?

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Steel is tough, and it can easily be shaped, cut or made into wire. Special alloys of steel can be made by adding small amounts of other metals such as aluminium, nickel and copper. Alloys give steel unusual hardness, toughness or ability to resist rust. Steel is often called the backbone of modern industry. Almost everything we use is either made of iron or steel or has been made with tools and machinery of these metals. Ships, trains, trucks and autos are made largely of steel. Even the safety pins and the needles you use are made from steel. Oil wells are drilled with steel machinery. Steel pipelines transport oil. Minerals are mined with steel equipment. Farm machines are mostly steel. Large buildings have steel framework.