On any serious industrial project the moment arrives when someone asks: "is this welder on UNE-EN ISO 9606 or on AWS?". The doubt is fair: both homologate welders through a practical test, but they belong to different regulatory frameworks and are not freely interchangeable.
UNE-EN ISO 9606, the European standard
UNE-EN ISO 9606-1 homologates the welder for steels (Part 5 covers titanium) and is the reference across the EU. It works alongside EN ISO 15614 for procedure qualification (WPQR) and EN ISO 3834 for welding quality management, plus EN 1090 on structural work.
AWS D1.1, the US code
AWS D1.1 (Structural Welding Code: Steel) governs structural welding in carbon and low-alloy steel in the United States, with its own criteria for procedure qualification, welder qualification and acceptance.
Where they diverge
- Territory: ISO 9606 dominates Europe, Latin America and the Middle East; AWS D1.1 rules the US, Canada and American-led projects.
- Focus: AWS D1.1 is vertical (steel structures); ISO 9606 is cross-cutting, homologating the welder across sectors.
- Currency: ISO 9606 needs six-month confirmation; AWS D1.1 keeps the qualification while the welder stays on that process.
- Testing: both rely on radiography or destructive testing, with comparable requirements.
When they coexist on one project
On EPC projects with a US licensor executed in Spain, contracts often call for both standards at once. The most seasoned welders end up holding both homologations.
What to ask your supplier
If the work is in Spain or another EU country, demanding UNE-EN ISO 9606 is the norm. If the client is US-led, ask for AWS D1.1 in parallel. Never accept a "generic equivalence": insist on both certificates.
Iron Pulse mobilizes welders with both homologations. Meet our UNE-EN ISO 9606 and AWS welders or talk to the team.
