Main aim of this article is to present results of the basic research in the area of the fatigue of material. The work was focused on the improvement of the computational support (for the FEM approach) for the material fatigue evaluation. Tested parts were exposed to vibrations and therefore was noticed higher risk of the failure caused by the vibration-fatigue. The real testing is described in this work. Effect affecting the fatigue life are discussed also. Parts were made of steel DC01. Modern simulation tools and testing devices are used for improving knowledge in this field. For the testing was developed special testing stand.