Temperature controlTemperature control in friction stir weldingFriction stir welding (FSW) is crucial for achieving desired weld properties, particularly in aluminumAluminum applications. Maintaining a consistent temperature, even with changing boundary conditions, allows better control of the material’s thermal history. This control facilitates the development of welding parameters and ensures uniform properties along the weld length. Proportional-Integral-Derivative (PID) control methodsControl method can maintain constant temperatures during FSW. These controllers must be specifically tuned to the alloy, material thickness, tool geometry, and machine. The heat generation of aluminumAluminum is alloy dependent this PID gains should be tuned for welding in a specific alloy. However, there are ranges of gains that can perform similarly in the same alloy, thus gains should be tuned to achieve acceptable performance for the application. We have demonstrated that optimal gains vary with different welding thicknesses of the same alloy and similar thicknesses of the different alloys.