Modern steels are made from cast iron by reducing its high carbon content to 0.08–2.1 percent by weight. Steel’s physical properties handily beat those of the hardest stones, as well as those of the other two most common metals. Granite has a similar compressive strength (capacity to withstand loads that shorten the material) but its tensile strength is an order of magnitude lower: granite columns bear their load as well as steel, but steel beams can bear loads 15–30 times higher.[50] Steel’s typical tensile strength is about seven times that of aluminum and nearly four times that of copper;
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