Stress (in MPa) vs. percent elongation for different steel types and their applications in body structure
Percent Elongation : The amount of elongation that a tensile specimen undergoes during testing provides a value for the ductility of a metal. The percent elongation is the ratio of the change in length of a specimen from zero stress to failure, compared to the original length, the quotient is then multiplied by 100 %.
% Elongation = (Lf - Lo) / Lo x 100%where,
Lo = initial length
Lf = length at fracture