An estimation of fatigue strength of automobile components was made by use of standard test specimen. Due to its complexity and its high costs, testing the final product of automobile components is generally difficult. Hence, tensile and fatigue test of standard test specimen obtained from raw materials of three automobile components were performed. Hardness of automobile components and their raw materials were measured to consider the change of material from the raw materials to the final products by various heat treatments. Fatigue limit modification method was investigated using the database of standard specimen according to the loading type, stress concentration and surface finishing. Finally, the modified fatigue limit by use of standard test specimens based on the hardness and the database compared with the fatigue limit of final products of three automobile components, stabilizer, spindle, engine bracket, respectively. The modification method proposed in the study provides resonable design criteria for the fatigue strength of actual automobile components.
