The stress‐strain relations for the cold working of the ductile metals are described for a group of cases assuming that the stresses under which they yield plastically depend only on the permanent parts of the strains, leaving out of the consideration the influence of the elasticity and of the speed of the plastic deformation. The behavior of the metals in the strain‐hardening range is expressed by means of a strain‐hardening function which connects the octahedral shearing stress with the octahedral unit shear. These variables are defined for strains of finite magnitude.