Friction stir welding is a solid-state joining process that uses a non-consumable tool to join two facing workpieces without melting the material. Heat is generated by friction between the rotating tool and the workpiece material which leads to a softened region near the FSW tool Friction Stir Welding (FSW), invented by Wayne Thomas at TWI Ltd in 1991, overcomes many of the problems associated with traditional joining techniques. Friction welding is also used with thermoplastics, which act in a