Home Ductility Ductility The ability of a material to deform plastically without fracturing, being measured by elongation or reduction of area in a tensile test, by height of cupping in an Erichsen test or by other means. Most common steels are quite ductile and as a result can accommodate local stress concentrations. Brittle items such as glass cannot accommodate concentrations of stress due to a lack of ductility and such, fracture before deforming under a tensile load. Ductility largely depends on a material’s chemical composition, crystalline structure and the temperature at which the ductility is being measured. < Glossary