The nonlinear material metallic rubber is used widely in engineering, especially in isolation systems. This paper describes the effects of loading processes on dry friction damping performance, which is based on the Masing model and its derivations. First, the primary loading lines of the full hysteresis loop are obtained from single axial experiments. The lines are used to describe the full loop in the process of coordinate transform. Then, two-dimensional perpendicular loading experiments are conducted to investigate the relationship between axial loading and tangential loading. In the experiments, different loading amplitudes in axial and tangential directions are adopted to study their effects on the damping performance. Particular attention is paid to the description of the relationship between relative frictional force and the displacement in its perpendicular direction. In addition, a test rig is designed for the study.