The applicability of the Ludwik, Hollomon, Swift and Voce equations in describing the stress - strain curves of metals was investigated. Calculated uniform strain values were found to depend on the equation used. Even when the Hollomon equation gave a high linear correlation coefficient in log-log coordinates, the strain-hardening exponent n could give an erroneous uniform strain. The equation with the lowest standard error of estimate gave the uniform strain nearest to the value obtained by direct measurement from the load-elongation curve.