This research topic focuses on the friction stir welding (FSW) process. The study focuses on the correlation between the process parameters (feed speed and rotational speed) and the mechanical and microstructural characteristics of the 5083 H111 aluminum alloy sheets 4 mm thick placed end-to-end and welded by a vertical milling machine from. This experimental approach is based on the variation of the depth of penetration of the shoulder of the tool, allowing to contribute to mastering the axial force in order to predict the welding process area for this grade of aluminum by the welding process FSW. Then, tensile and hardness test were done to investigate the mechanical properties of the weld. The optimum process parameters were determined with reference to grain size, ultimate tensile strength and hardness. In addition, microhardness profiles allow to give the importance of the influence of the studied parameters on the different zones of the weld.