Swaged bolts are an alternative to high strength bolts in steel structures. To clarify the steps of the installation process, numerical modelling has been carried out. The relevant phenomena are described and evaluated. This numerical calculation accounts for large displacements, large strains, mechanical plasticity and friction contact between the components of swaged bolts. The non-linear finite element code ''Lagamine'' designed for the simulation of metal forming processes has been used to provide the stress distributions in the components.