<p>Tube hydroforming (THF) is a less frequently used advanced manufacturing technique that uses pressurized fluid in place of hard tooling to plastically deform the tubular blank into the desired shape. In the THF process, the tubular blank is first placed between two semicircular die pieces. It is then filled with water and deformed into its final shape by simultaneously applying fluid pressure and axial compressive forces using a water intensifier system through axial punches. Tube hydroforming is mainly used to produce hollow components using tubular blank. Hollow components from tubes of austenitic stainless steels find applications in the automobile industry, particularly for exhaust systems. Forming limits of tube material not only provide information on safe working loads but also ensures better component performance. Experimental determination of forming limits is laborious and expensive as it takes a lot of time and resources like materials and machines. The present work deals with the prediction of forming limits for tubes by numerical simulations. Thus, in this work, forming limits of tubes of austenitic stainless steel (AISI304) predicted with finite element-based simulation using PAMSTAMP 2G solver for straight tube (seamless tube) and welded tube (seam tube) and forming limit diagram (FLD) is drawn. Then the data was compared for the effect of the weld line on the formability of tubes. It was found that the weld line has a significant effect on the formability of tubes, technically, the weld line has lowered the formability of the weld tube when compared to the seamless tube by an amount of 12 percent. The microstructure analysis of fractured tensile samples from the welded and unwelded regions of the tubes revealed differences in grain size gradient and phase fractions.</p>