The quantities commonly used to define ductility in a tension test are percent elongation (sometimes denoted as \varepsilon_f) and reduction of area (sometimes denoted as q) at fracture.Dieter, G. (1986) Mechanical Metallurgy, McGraw-Hill, Fracture strain is the engineering strain at which a test specimen fractures during a uniaxial tensile test. Percent elongation, or engineering strain at fracture, can be written as:
