T Thin wall casting (TWC) technology opens up opportunities for nodular cast iron (DI) to compete with aluminum in terms of weight. So far, aluminum has been the preferred material in automotive because aluminum is known as a light weight material. The use of lightweight materials in automotive components will reduce weight so that fuel consumption becomes efficient. The success of TWDI casting is determined by the accuracy of the casting speed. The purpose of this study was to test the fatigue of the connecting rod component with an I-beam thickness of 2 mm which has been reduced by the weight of the component from the original I-beam thickness. Due to the need to carry out fatigue testing of components, it is necessary to make fatigue test equipment first by using the fatigue test equipment so that the fatigue limit of each component being tested can be determined. The fatigue test on the components is carried out by applying a dynamic compressive force with a cycle of 1 million with a force of 17.630N. Some of the tests carried out were compression testing, micro testing, macro testing and analysis and explanation of the connecting rod components. So from the results of this study, it is necessary to pay attention to the micro structure so that the connecting rod can be even better and in accordance with the standard.