Abstract
Variable loading fretting fatigue tests were performed using two-step multiple stress and SCM435 steel. Varialbe stresses used in the experiment consist of two stresses. One of them is a stress equal to fretting fatigue limit under full-reverse constant load. Another is chosen so that amplitude and mean are within the unbroken region in fretting fatigue limit diagram. Fretting fatigue failure occurred even if the variable stress didn't contain the stress above fretting fatigue limit under constant load. Consequently, fretting fatigue limit under variable load is considerably lower than that under constant load.
