The susceptibility to deep processing in the industrial wire drawing process has been investigated in the research paper regarding the copper grade influence on the process. The conducted research included the identification of the mechanical and electrical properties of wires manufactured from Electrolytic Tough Pitch Copper (Cu-ETP) wire rod and Oxygen-Free Copper (Cu-OF) cast rod in terms of the applied deformation. In particular, as main contribution of this research to the scientific and industrial community a mathematical model describing the wire strengthening and softening characteristics was determined.