Flat, convex and concave wedge tools can all be used in cross-wedge rolling (CWR) processes. However, using concave tools requires a new generation of rolling mills with segmented tool assemblies. This paper presents the concepts for such a machine. Next, the influence of tool shape on the CWR process is analysed using the example of a stepped shaft. This analysis was based on numerical simulations carried out using the Simufact.Forming software. The distributions of temperature, effective strain and damage function, as well as force and energy parameters, were compared. Based on this analysis, the most effective CWR process variant was selected.