Friction stir welding (FSW) is the most important advancement in metal joining technology for joining high-strength aluminium alloys. The input process parameters, including tool rotational speed, travel speed, and axial load, must be optimized in order to increase the reliability and quality of the products made by the FSW process. To identify the optimum parameters, the Taguchi design of experiment (DOE) approach was utilized. Taguchi�s L9 orthogonal arrays were used to assess and determine the optimal condition, and the results were submitted to S/N analysis and analysis of variance (ANOVA) to identify the important welding factors impacting weld quality. The important parameters for each welding performance criterion, such as residual stress, were evaluated using ANOVA. The optimal parameters obtained are 450 rpm for the tool rotation speed, 350 mm/min for the travel speed, and 900 kg for the axial load. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.