Abstract: A new radial fretting test rig has been developed by modifying the clamps and the control programs of conventional tangential fretting apparatus. Thus simulated fretting tests can be carried out with imposed load or imposed deformation mode. The speed of relative movement between the contacting pairs can be controlled by changing the speed of loading (or frequency). The apparatus can well simulate radial fretting situation, and the test results based on different testing modes are comparable with each other and have good repeatability.