After chemical mechanical polishing (CMP) of oxides became a standard method for global planarization, the polishing of metals is now being embraced by manufacturing. Although tungsten CMP has been used for subhalf-micron technologies for quite some time, there is still a lack of theoretical understanding and modeling of the metal CMP processes. This paper presents a mathematical approach to describe erosion and dishing for tungsten CMP. The model, which represents the pad by a network of springs, simulates the profile of a dished tungsten line. The calculated data are then compared with experimental data.