The main topic of the diploma thesis is to verify strength of backplates in automotive industry. Braking system is the main safety component and therefore strict international uniform rules apply to it. Because of this, high emphasis is placed on the quality of various conditions, which are tested in detail relating to all types of load, even upon various conditions in various environments. In our testing we focus on static and dynamic test of backplates made of two different materials – S420 and S550. The thesis is divided into theoretical and practical part. The theoretical part contains general knowledge of characteristics related to the material fatigue load, studies on fatigue process, spreading and stages of cracks. The practical part deals with static test of tension load until the backplates is prolonged by required value. Dynamic test consists of highly cyclical putting of tensile strength in up to the backplates rupture. Both tests are carried out on MTS Load Frame. The thesis conclusion is dedicated to the comparison and evaluation of obtained results and knowledge of the testing.