The plastic properties of commercially pure copper are considered. Using the strain diagrams (for strain rates of 0.002, 0.016, 150.0, 2000.0, and 13300.0 s−1) and the hardening curve for copper under static compression, the analytical dependence of copper yield stress on strain (in the range from 0 to 0.45) and strain rate (in the range from 0.002 to 13300.0 s−1) is found.