In this paper, we present the analysis of results of experimental studies of energy dissipation and variations of the transverse strain coefficients under quasistatic tensile stress of metals. The nature of changes in these processes at different stages of deformation is considered: elastic, nonlinear, transition from elastic to developed plastic flow, and developed plastic flow. It is shown that at all stages there is a correlation of changes in independently measured strain parameters: temperature, transverse strain coefficients, and hardening. The decisive effect of the interaction potential anharmonicity on the nature of the processes of changes in modules and dissipation at the nonlinear stage of deformation is discussed.