Many engineering machines and mechanical components are subjected to fluctuating stresses, taking place at relatively high frequencies and under these conditions failure is found to occur. This is "fatigue failure". And this led to the invention of a fatigue testing machine. In view of effective design that will not fail accidentally, this research is conceived. This testing machine will determine the strength of materials under the action of fatigue load. Specimens are subjected to repeated varying forces or fluctuating loading of specific magnitude while the cycles or stress reversals are counted to destruction. The first test is made at a stretch that is somewhat under the ultimate strength of the material. The second test is made at a stress that is less that than that used in the first. The process is continued, and results are plotted.