The paper deals with the results of experimental investigations of surface residual stresses occurring after quenching 42CrMo4 heat-treatment steel specimens having different masses. The specimens with two different square cross-sectional areas, i.e., of 25 x 25 mm and 35 x 35 mm respectively, but with the same length, i.e., 50 mm, were chosen. Such specimens permitted the investigation of the quenching process and surface residual stresses occurring after quenching from the viewpoint of the influence of specimen mass. For an efficient study of this influence, only one quenching agent was selected, i.e., a 15% polymer water solution. To eliminate the influence of residual stresses due to transformation, quenching was carried out using the specimens given, first from the quenching temperature (T(A) = 860 degreesC) and then from a temperature of 620 degreesC. The data obtained provide valuable information in attempt to provide compressive surface stress state after quenching process.