Overview
EN ISO 25239-3:2020 - "Friction stir welding - Aluminium - Part 3: Qualification of welding operators" specifies requirements for the qualification and certification of welding operators performing friction stir welding (FSW) of aluminium and aluminium alloys. Published in 2020 (second edition) and adopted by CEN as EN ISO 25239-3:2020, the standard replaces the 2011 edition and aligns operator qualification with the ISO 25239 series. It does not apply to the term “operators” as defined in ISO 25239‑1 and excludes friction stir spot welding (covered by the ISO 18785 series).
Key topics and requirements
- Scope and exclusions: Focused on FSW of aluminium; excludes spot welding and certain ISO‑defined operator roles.
- Qualification routes: Defines acceptable tests for operator qualification:
- Standard welding test
- Welding procedure test
- Pre‑production welding test
- Production sample welding test
- Essential variables & ranges: Qualification is controlled by essential variables such as:
- Friction stir welding methods
- Welding equipment and unit operation
- Parent aluminium materials and alloys
- Weld joint geometry
- Quality acceptance levels
- Test welds and acceptance: Specifies preparation, testing, acceptance levels, and re‑testing requirements for qualification welds; references acceptance criteria from ISO 25239-5.
- Certification and validity: Certificates are issued on successful qualification; initial validity has been extended to three years with possible prolongation for another three years.
- Knowledge requirements: Annex A and B require documented knowledge of the welding unit (equipment operation) and welding technology (FSW principles and process control).
- Documentation: Annex C provides an example qualification certificate format.
Notable changes in this edition include updated acceptance level references, removal of NDT as an alternative to bend testing for operator qualification, and extended qualification validity.
Applications and users
This standard is crucial for organizations that deploy FSW on aluminium components, including:
- Welding coordinators and quality managers
- Training and certification bodies
- Manufacturing engineers in aerospace, rail, marine, automotive, food processing and consumer goods
- Fabrication shops using FSW equipment and robotic FSW cells
- Inspectors and procurement teams specifying operator competence and traceable certification
Using EN ISO 25239-3:2020 helps ensure consistent operator competence, traceable certification, and compliance with industry quality and inspection requirements for aluminium FSW.
Related standards
Keywords: EN ISO 25239-3:2020, friction stir welding, FSW, aluminium, qualification of welding operators, welding operator certification, welding tests, acceptance levels, welding procedure.