The main objective of this work is the analysis of hydroforming for the manufacture of joint bellows of AISI 316 steel for different values of diameter. The initial thickness of the metallic tube is of I min and diameters between 500 and 1200 mm are considered. The Finite Element Method is applied to study the tensile stress and thickness reduction at the wave peak of the final part. The numerical results are compared to the recommendations given by the EJMA standard. More critical values of wave thickness and tensile stress are predicted by simulation.