Metal additive manufacturing of stamping tool and die has a potential of reducing the lead time of forming processes, while at least not increasing the cost. As a part of a research project exploring the possibilities to use this type of tool manufacturing techniques, topology optimization using LS-TaSC has been utilized and one example case is presented in this paper, namely a U‑bend tool. This paper looks at the possible benefits from using nonlinear simulations in topology optimization, the effect of chosen target mass fraction value, the interpretations needed of optimal results and the effects on the formed specimen after using an optimized tool. Results show that accounting for the time dependent pressure on the tool, rather than applying a form of equivalent static load, gives a different optimal topology. Some manual interpretations of the optimal results are also recommended, as well as studying the effects on the specimen from removing material on the tool side.