<p>The numerical analysis of material flow in the friction stirs welding process remains challenging, primarily due to the difficulty of simultaneously incorporating the effects of several input parameters into the simulation. This study investigates the influence of three key process parameters tool rotation speed, welding speed, and tool pin profile on material flow, using numerical simulations conducted across four different levels of each parameter. The simulation results reveal that material flow velocity is strongly influenced by the tool pin profile and tends to increase with higher tool rotation speeds, while the effect of welding speed is comparatively minimal. Among the different pin profiles, the T4 profile tool achieves the highest peak material flow velocity of 1.22&#xa0;m/s at 1400&#xa0;rpm across all welding speeds, attributed to the presence of a step feature in the tool design. Moreover, the developed numerical model is validated against experimental temperature profiles to ensure its accuracy.</p> Graphical Abstract <p></p>