Joining by plastic deformation is needed in applications such as joining of similar and dissimilar metal parts, fluid transmission pipeline, aircraft and automobile components. This paper presents a new plastic deformation technique to connect sheet to tube in one pass of dissimilar material. A single pass joining is accomplished to produce bosses and a tube lip edge over flat sheet. The tube constrained length and tube lip height were checked by finite element analysis (FE) and experimental testing. Aluminum tube specimens with 48 mm outer diameter and 2 mm initial thickness were used. Tube lip height of 6, 8, 10, 12 and 14 mm and constrained length of 6, 8, 10, 15, 20, 25, 30 and 35 mm were used to form the boss part. Minimum punch nose radius was used to produce severe deformation of the tube lip over sheet surface as well as to avoid the tube lip curls. The tube passes through several stages until it is connected with the metal sheet, partial flare-bend, partial boss forming and the seaming stage. A new design of the punch was used to control the internal tube diameter and prevent the inward tube flow during the deformation process. Good agreement was found when comparing FE to experimentally-obtained results concerning deformation stages, trend of load/displacement curves.