Ductility, << duhk TIHL uh tee, >> is the ability of certain solids to undergo permanent changes in shape without breaking. For example, a piece of copper can be drawn (stretched out) to make a thin wire. A brick’s shape, on the other hand, cannot be permanently changed except by breaking it.
Ductility is a valuable property of many metals, including aluminum, gold, iron, nickel, and silver. These metals can be drawn into wire, hammered into various shapes, or rolled into sheets. The term malleability is often used in place of ductility to describe the property of metals that allows them to be hammered into thin sheets. Metals are not the only ductile substances, and not all metals are ductile. For example, modeling clay is a ductile nonmetallic substance and impure tungsten is a nonductile metal.
