Subscribe to our newsletter to receive the latest news and events from TWI:

Subscribe >
Skip to content

Friction Stir Welding

Joining Technologies Banner
Innerpage Title Banner
Contact Us CTA
Friction Stir Welding (FSW), invented by Wayne Thomas at TWI Ltd in 1991, overcomes many of the problems associated with traditional joining techniques. FSW is a solid-state process which produces welds of high quality in difficult-to-weld materials such as aluminium, and is fast becoming the process of choice for manufacturing lightweight transport structures such as boats, trains and aeroplanes.

Fabricators are under increasing pressure to produce stronger and lighter products whilst using less energy, less environmentally harmful materials, at lower cost and more quickly than ever before. FSW, being a solid-state, low-energy-input, repeatable mechanical process capable of producing very high-strength welds in a wide range of materials, offers a potentially lower-cost, environmentally benign solution to these challenges.

FSW was invented and pioneered by TWI Ltd. Accordingly, we have a wealth of experience of applying the process industrially, in addition to in-depth knowledge of the fundamental science that underlies it.

Process Overview

FSW is a solid-state joining process that creates high-quality, high-strength joints with low distortion and is capable of fabricating either butt or lap joints, in a wide range of material thicknesses and lengths.

In the process a rotating FSW tool is plunged between two clamped plates. The frictional heat causes a plasticised zone to form around the tool. The rotating tool moves along the joint line. A consolidated solid-phase joint is formed.

FSW being a solid-state process eliminates many of the defects associated with fusion welding techniques such as shrinkage, solidification cracking and porosity.

TWI’s Members include many of the world’s suppliers of FSW equipment.

Friction Stir Welding - Benefits for Industry

For more information please email:


contactus@twi.co.uk