Friction stir welding (FSW) could move from pilots to mainstream production with a new “self-fixturing” setup from Pacific Northwest National Laboratory. The lab reports that FSW’s long-standing barrier—the need for a rigid, perfectly shaped anvil to absorb forces up to ~5,000 lb (2268 kg)—has limited use on complex auto parts and typical line layouts. The new approach is designed to remove that constraint and make FSW more practical on assembly lines.

The self-fixturing friction stir attachment, shown here, eliminates the need for a separate anvil and can be attached to the end of a robotic arm. (Illustration by Mitch Blocher and Derek Munson | Pacific Northwest National Laboratory)--PNNLPNLL

The system places a compact backing plate and the FSW tool on the same robotic attachment, effectively pinching the workpiece and eliminating the separate anvil. PNNL is adding a hydraulic mechanism to capture the tool’s forces in a closed loop so the robot mainly handles positioning rather than load bearing—an important step for standard industrial robots.

If validated at scale, the method could extend FSW beyond flat sheets to parts like roof rails and door frames, areas that still lean on spot welding or adhesives. PNNL notes prior auto work welded flat sheets before stamping; the self-fixturing design aims to bring FSW directly to shaped structures, promising lighter materials, stronger welds, and lower energy use than fusion welding.

A friction stir-welded car door made possible by PNNL's advanced manufacturing research. (Photo: TWB Company, LLC.)

The lab plans to package the tool into an “industry-hardened” unit for real lines. The research is supported by the U.S. DOE Vehicle Technologies Office. No production timeline is given, but the target is clear: bring friction stir welding into routine, automated manufacturing.

💡
Would you like to receive newsletter weekly?! Subscribe for free, also get full access to the website.
Subscribe