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Friction Stir Welding Bridges the Gap

Wed, 02 February, 2022

TWI has been developing the AdStir technique, using filler wires to add material into the gap between components to overcome issues related to alignment and condition of supply. Railcar manufacturers have shown great interest in this technology.

The next challenge was joining fabricated subassemblies together where larger gaps are possible, which cannot be joined by AdStir alone. This challenge has been met by the development of a unique technique called Friction Stir Gap Bridging. The image below shows two 4mm plates with a 5mm joint gap between them, joined together using this technique with no significant weld cap underfill.

This development opens up the use of FSW to join components together without all the costs of pre-machining of large structures.

If you are interested in this development and would like to know more, please contact us below (FAO Sam Wei).

For more information please email:


contactus@twi.co.uk