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.