This research is to test the fatigue endurance of the material by using end bending of specimen. The testing material is S45C steel and forming to the standard size for testing. The specimens with a diameter of 8 mm required a different bending moment. It was found that the large bending moment affects the fatigue of the specimen. The specimen quickly damaged due to the high bending stress and there were a small number of load cycles. If the bending moment acting on the specimen was reduced to the bending stress decreased and the number of load cycles increasing. It was shown that the bending stress and the magnitude of the bending moment affected the fatigue of the material. Also the appearance of damage marks of the specimen will have a flaw around the fracture surface. Then the flaw will be enlarged until the specimen will be damaged by fracture.

The purpose of this research was to construct the rotating bending fatigue testing machine for metal material to find out the built-in machine performance and compare it with machines that meet international standards. The machine built into a compact machine using weight knob for a heavy load in testing. It can test the force range 50-300 Newton (N) the motor is a 1 HP transmitter with a speed of 2800 rpm. Start by pressing the Start button to release the weight that sends power to the workpiece and attend a sensor counting is available to detect the lack of testing material. For the efficiency performance of the machine uses 10 piece steel shafts diameter of 8 mm according to the standard of the material fatigue tester by independent end bend rotation. For testing to compare with the test international standard machine also uses 10 piece steel shafts using force 150 N. For the analysis to test statistical hypotheses with the Minitab computer program at the significance level of 0.05 it was found that the values obtained from be made the rotating bending fatigue testing machine for metal material there is no difference with standard machines from statistically significant. All values are within the set limits. In conclusion the machine was created to be as effective as the international standard machine.