<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (October 2008) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (October 2008) (Learn how and when to remove this template message) </Td> </Tr> <P> Ductility is a measure of a material's ability to undergo significant plastic deformation before rupture, which may be expressed as percent elongation or percent area reduction from a tensile test . According to Shigley's Mechanical Engineering Design--10th Ed . significant denotes about 5.0 percent elongation (Section 5.3, p. 233). See also Eq. 2 - 12, p. 50 for definitions of percent elongation and percent area reduction . Ductility is often characterized by the material's ability to be stretched into a wire . </P> <P> From examination of data in Tables A20, A21, A22, A23, and A24 in Shigley's Mechanical Engineering Design--10th Edition for both ductile and brittle materials, it is possible to postulate a broader quantifiable definition of ductility that does not rely on percent elongation alone . In general, a ductile material must have a measurable yield strength, at which unrecoverable plastic deformation begins (see Yield_ (engineering)), and also must satisfy one of the following conditions: either have an elongation to failure of at least 5%, and / or area reduction to rupture at least 20%, and / or true strain to rupture at least 10% . </P>

Ductility is the ability for a metal to be