Grenzebach FSW friction stir welding

What is friction stir welding? Explained easily.

In friction stir welding (FSW), metals are stirred, not melted. The friction stir welding process is particularly suitable for joining non-ferrous metals with low melting temperatures as well as dissimilar metal welds.

Definition: What is friction stir welding?

FSW (friction stir welding) is a pressure welding process. During this innovative welding process, metals are stirred at their seam with a rotating tool and – in comparison to the arc and laser beam welding processes – are not melted. The seam is heated but joined in a still solid state. Therefore, friction stir welding is in particular suitable for joining aluminum alloys, mixed joints and technically pure metals.

Free web seminar: "Explained in 30 minutes: Friction stir welding – the potential"

Concise knowhow in only 30 minutes – David Schwebel, Head of Strategic Developments, NA at Grenzebach, will answer any open questions and show you the potential of friction stir welding.

When: Tuesday, May 24, 2022, at 11 AM (Eastern Standard Time)

Take your production to the next level – sign up for the web seminar now!


Process: How does friction stir welding work?

The conventional FSW process is easily explained in four simple steps:

Friction Stir Welding Step 1:Rotating welding tool

1. Rotating welding tool

A wear-resistant tool is set in a spindle and rotates.

Friction Stir Welding Step 2: Immersion

2. Immersion

The rotating tool dips directly into the material to be joined using axial force.

Friction Stir Welding Step 3: Feed

3. Feed

Frictional heat is generated by rotation and pressure. The metal becomes plastically deformable and is stirred and compacted by the tool moving forwards along the seam. The melting point of the material is thereby not reached.

Friction Stir Welding Step 4: Removal

4. Removal

The tool is lifted off the seam. The result is a strong, media- and pressure-tight joint between the workpieces.

Application: What can be welded?

FSW is suitable for joining non-ferrous metals and alloys with low melting temperature and dissimilar metal welds:

  • Aluminum
  • Copper
  • Magnesium


    FSW is particularly effective when processing aluminum

    It enables the joining of aluminum alloys, e.g. the 3000, 5000 and 6000 series, which are considered to be non-weldable or difficult to weld. It is also an ideal process for welding dissimilar metals, such as aluminum sheets or extruded profiles with die-cast aluminum. Friction stir welding is more resistant against material defects such as pores, blowholes and fire cracks than, for example, the fusion welding process.

      Friction stir welding is used in various industries:

      • Automotive, in particular in e-mobility: Cast and extruded battery trays for hybrid and BEV (Battery electric vehicle) models, heat exchangers and power electronics
      • Power transmission/ power electronics
      • Rail vehicle construction
      • Battery manufacturing
      • Aviation and aerospace
      • Consumer electronics

      Advantages: What are the benefits of friction stir welding?

      Excellent welding quality

      • Durable, media- and pressure-tight weld seams
      • High, reproducible seam quality
      • Robust, resilient and extremely load-bearing
      • No pores or hot cracks, as the material has no liquid or vapor phase
      • Low-warpage joints


      • Need for purchasing and storage of operating materials is reduced, since auxiliary materials such as shielding gas, powder or welding wire are not required
      • Low energy consumption compared to classic welding processes
      • Less preparation and post processing of seams necessary
      • Low reject rates thanks to the high robustness of the process

      Environmental and health protection

      • No contamination by dust, gases, smoke, radiation
      • Emission-free
      • Quieter than common welding processes
      • No auxiliary materials necessary, such as shielding gas, powder or welding wire
      • Essential step in the production of components for e-mobility (heat exchangers and battery trays)

      Friction stir welding: Your concerns, our solutions

      Friction stir welding (FSW) is a relatively new but at the same time forward-looking welding process for the industry to which we at Grenzebach are committed. We often receive questions and notice ambiguities regarding this process. We want to address your concerns and also show solutions.

      Grenzebach – Supplier for turnkey plants

      Grenzebach develops and supplies turnkey FSW plants – from gantry machines with customer-specific work areas to robots that can weld 3D geometries – and thinks ahead for the customers. Therefore, it is also key to consider the right technology of tools in addition to equipment technology. Based on customer requirements, the right friction tool is chosen: a one-piece (conventional) or multi-piece tool (DynaSTIR) with a rotating friction pin and fixed shoulder.

      For North America

      Your contact person: John Fluker

      Do you have questions about friction stir welding? Would you like to know whether a new idea can be implemented with FSW? Or do you need support in selecting a system? Please contact us. We'll be happy to advise you!

      For all other regions

      Your contact person: Sahin Sünger

      Do you have questions about friction stir welding? Would you like to know whether a new idea can be implemented with FSW? Or do you need support in selecting a system? Please contact us. We'll be happy to advise you!

      Sahin Sünger Grenzebach