The standard exchange current densities pertaining to electron transfer processes at electrodes are employed to estimate chemical hardness of various metals. This is accomplished by deriving a new parametric relation for hardness in terms of the work function and surface potential of electrons. Hydrogen evolution and ferric/ferrous redox reactions are considered as examples to extract chemical hardness from electrode kinetic data. The surface potential is calculated for a large number of metals using phenomenological thermodynamic considerations. The significance of the methodology is also illustrated by calculating the potential of zero charge of metal/solution interfaces, thus demonstrating that equilibrium as well as kinetic studies in electrochemistry are capable of yielding the hardness of metals.