Identify the cause of the failure of parts for all relevant including consumers and producers is important. For example, from the perspective of the consumer determine the cause of failure pieces can be legal aspects and from the point of view of the manufacturer to reform the process and avoid its repetition. Most failures were reported in the world is Fatigue-related failure. This failure occur under cyclic stress and tensions much lower than the tensile strength of the piece without warning and suddenly. In this study, using a laboratory chemical analysis, hardness, microstructure and fracture surface analysis main cause of failure of a Nissan car was studied. The studies conducted showed avulsion and fine cracks in the surface due to rough machining and river lines of fatigue failure in the piece surface which eventually led to its failure.