Fatigue of metals is a final bachelor thesis where is discussed three different methods to analyze the results of a fatigue test: The Wöhler curve, the Weibull distribution and the Gumbel distribution. From the results of the fatigue test of different kind of springs and different kind of welded joints, have been analyzed using the Software ProFatigue which give the distributions of Weibull and Gumbel for each test. Then, these distributions have been compared between them and with the Wöhler curve used in the fatigue tests. Finally, after got all the results, have been decided some conclusions about the different methods and which one could be better for work.