The aim of the present paper is to investigate the effect of stabilisation of the hysteresis loop under hard loading on steel C45E. C45E, which is widely used for the manufacture of shafts and characterised by its superior strength. Here, we experimentally investigate the phenomenon of plastic deformation stabilisation at rigid loading, depending on the amplitude and loading rate. Using the hysteresis loop at each cycle, we calculate the accumulated damage in the material during the stabilisation of plastic deformation.