Tensile test of an Aluminum alloy. The local necking and the cup and cone fracture surfaces are typical for ductile metals.

This tensile test of a cast iron shows low ductility.

Ductility is when a solid material stretches under tensile strain. If ductile, a material may be stretched into a wire. Malleability, a similar property, is a material's ability to deform under pressure (compressive stress). If malleable, a material may be flattened by hammering or rolling.