| Shaft hold important role in machine, such as pump, turbine, steam engine, etc. Spinning shaft that encounter a fluctuating loading, could occur a sudden fracture failure although the loading is below the material maximum strength. This fracture type is called fatigue fracture. There’re a lot of factors could affect fatigue life, like load, dimension, surface roughness, temperature and reliability. The study in this undergraduate thesis has function to find out the effect of surface roughness against fatigue life. This research method is using experimental research. It processed by test and analyzes three different type of surface roughness by using R. R. Moore testing device. Every kind of surface roughness will take different load. The research results show that surface roughness could affect fatigue life. The smaller surface roughness value, the longer fatigue lifetime will be received. |