In die casting design, residual stress and thermal deformation based FEM analysis are gaining enormous importance. Shiga et al. have reported that the thermal and residual stress of the I-shaped model could be more accurately predicted by using the elastoplastic-creep model than by using the conventional elasto-plastic model. In this study, factors affecting the contact forces between the die and the casting were analyzed by using a little more complicated model than the I-shaped model. The results clearly indicate that, irrespective of shapes, the plastic strain term affects the contact forces the most, and that the creep term further reduces the contact forces. Furthermore, a comparison between the simulated and measured values of the residual stress of an aluminum die-cast product confirms the superiority of the elasto-plastic-creep model than the elasto-plastic model in predicting the residual stress, which could also be used instead of the contact forces.