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In this paper the production of an I shape extruded profile with a seam weld in the middle section, suitable for mechanical testing, has been described and analyzed. This profile was produced both with and without material welding, by the use of a bridge before the flat die, thus reproducing the typical welding condition of a hollow profile extrusion. Different preheating temperatures of the billet, production rates and welding chamber heights were used and their influence on the weld quality was analyzed. The welded profiles were characterized by means of both tensile tests (strength, elongation and fracture strain) and crack propagation tests, in order to understand the relationships between process parameters, die design and weld properties. The experimental results reveal that the procedure involving specimen machining altered the microstructure distribution in the profile section, inspite of a lower scattering, the judgements about weld quality are to be considered in this case as fake. In the test procedure with non-machined specimens, the UTS was found to be the least sensitive parameter for weld quality evaluation, better results were found with true strain at fracture, although with a great scattering of the results. The crack propagation tests allows one to well discriminate seam weld quality with a rather small number of specimens, on the other hand, the conduction of the test is more complex and time consuming. The best weld qualities, almost comparable to the behavior of the unwelded profiles, have been obtained with the BB die geometry, the one with the biggest welding chamber