In this paper, residual stress distributions in rectangular bars due to rolling or burnishing at very high rolling or burnishing loads are investigated by roll burnishing experiments and three-dimensional finite element analyses using ABAQUS. First, roll burnishing experiments on rectangular bars at two roller burnishing loads are presented. The results indicate the higher burnishing load induces lower residual stresses and the higher burnishing load does not improve fatigue lives. Next, in the corresponding finite element analyses, the roller is modeled as rigid and the roller rolls on the flat surface of the bar with a low coefficient of friction. The bar material is modeled as an elastic-plastic strain hardening material with a nonlinear kinematic hardening rule for loading and unloading. The computational results showed that a higher rolling load does not necessarily always produce higher compressive residual stresses in the desired regions of the bar and gives better fatigue lives of the bar under bending as indicated from the experimental results. The computational results also showed that the longitudinal residual stresses are sensitive to the initial yield stress and the detailed strain hardening behavior assumed at large strains.