Abstract Bulk forming processes are widely used in both the primary and secondary metal working industry, especially for discrete parts production. In that field quite complicated final shapes are often required but the process planning and tool design are still based mainly on empirical rules and gained experience. In order to assist these substantial engineering activities, some computer simulation packages have been recently developed. Most current numerical investigations are based on the finite element method rather than on the former slip-line field analysis or upper-bound elemental technique. All the numerical solutions, however, should be confirmed by model material experiments or, at least, compared with another numerical analysis. Accordingly, the purpose of this paper is to indicate the influence of input data selection on the results obtained by finite element simulation of bulk forming processes. The values of the friction factor and the metal flow stress have been varied independently using the FORM-2D software code for computer simulation.