Learn about welder certification standards including ISO 9606, AWS, and ASME. Understand qualification requirements, testing methods, and documentation.
Introduction
Welder certification ensures that welders have demonstrated the skill to produce quality welds. At Fulei Metal, our welders hold certifications to international standards.
Why Certification Matters
Demonstrates welder competence. Required by many codes and clients. Ensures consistent quality. Provides traceability. Required for structural, pressure, and critical applications. Builds client confidence.
Major Certification Standards
ISO 9606
International standard for welder qualification. ISO 9606-1: steel. ISO 9606-2: aluminum. ISO 9606-3: copper. ISO 9606-4: nickel. ISO 9606-5: titanium. Each covers essential variables and test requirements.
AWS (American Welding Society)
AWS D1.1: structural steel. AWS D1.2: aluminum. AWS D1.6: stainless steel. AWS QC7: certified welder program.
ASME (American Society of Mechanical Engineers)
ASME Section IX: pressure vessels and piping. Most rigorous qualification. Required for pressure equipment.
EN 287
European welder qualification (superseded by ISO 9606). Still referenced in some documentation.
Essential Variables
Process
TIG, MIG, Stick, etc. Each process requires separate qualification. Change in process requires re-qualification.
Material Type
Material groups (P-numbers). Steel, stainless, aluminum, etc. Qualification covers similar materials within a group.
Thickness
Qualification range depends on test thickness. Typical: test at 3 mm covers 1.5-6 mm. Thicker tests cover wider ranges.
Position
Flat, horizontal, vertical, overhead. Each position requires separate qualification. 6G (pipe, 45 degrees) covers all positions.
Joint Type
Butt, fillet, etc. Butt qualification may cover fillet. Fillet does not cover butt.
Filler Metal
Filler classification. Similar fillers within a group.
Shielding Gas
Gas type and composition. Change may require re-qualification.
Testing Methods
Visual Inspection
Weld appearance. Bead shape and size. Surface defects. Dimensional compliance.
Bend Test
Specimen bent to specified radius. Checks ductility and fusion. No cracks or defects larger than specified. Most common test.
Radiography
X-ray of the test weld. Reveals internal defects. Porosity, lack of fusion, cracks. More expensive than bend test.
Macro Examination
Cross-section of weld. Polished and etched. Shows penetration, fusion, bead shape. Used for procedure qualification.
Certification Process
- Select standard and essential variables. 2. Prepare test coupon. 3. Weld under supervision. 4. Inspect visually. 5. Perform mechanical tests. 6. Issue certificate if passed. 7. Maintain records.
Certification Renewal
Typically valid for 3 years (ISO) or 6 months without use (AWS). Renewal requires: continued use of the process. Employer signature. No significant lapse. Re-testing if lapsed.
Documentation
Welder qualification certificate. Essential variables covered. Test results. Supervising inspector signature. Expiration date. Maintained in quality records.
At Fulei Metal
Our welders are qualified to: ISO 9606 for steel and aluminum. Client-specific requirements. Process-specific qualifications (TIG, MIG, laser). We maintain current certifications and re-qualify as needed.
Conclusion
Welder certification demonstrates competence and ensures quality. At Fulei Metal, our certified welders and documentation provide confidence that your welds meet international standards.
Welder Qualification Versus Procedure Qualification, and What Expiry Really Means
The most common confusion in a documentation package is between qualifying the procedure and qualifying the person. They are separate documents, with separate scopes and separate expiry mechanisms.
| Document | What it qualifies | Issued to | How it stays valid |
|---|---|---|---|
| ISO 15614-1 | The welding procedure, by test, producing a WPQR | The fabricator | It remains valid while the procedure is unchanged; a change to an essential variable requires re-qualification |
| ISO 9606-1 | The welder, for fusion welding of steels | The individual welder | Two years, conditional on the employer confirming continued work within scope every six months |
| ISO 9606-2 | The welder, for aluminium and its alloys | The individual welder | Same two-year and six-month structure |
| ISO 14732 | Welding operators for mechanised and automatic equipment, and resistance weld setting operators | The individual operator | Same structure, with scope defined by equipment type rather than by manual position |
| ASME Section IX | Both the procedure, as PQR and WPS, and the person, as WPQ | Fabricator and individual | Continuity of practice, generally verified at six-month intervals rather than a fixed expiry date |
| AWS D1.1 | The welder, for structural steel work | The individual welder | Continuity of practice, with re-testing if the welder is out of the process for an extended period |
Scope is what makes a certificate meaningful, and it is what most often gets overlooked when a package is checked. A welder qualified on 10 mm plate in the flat position is not automatically qualified on 2 mm sheet in the vertical position, and a procedure qualified on carbon steel says nothing about stainless. When a buyer reviews a package, the question to ask is whether the scope covers the joint on the drawing, not merely whether a certificate exists.
Two practical cautions when reviewing documentation. A WPQR records a test result, not a promise: it tells you the procedure passed the specified tests at the time it was qualified, which is why essential variables matter. And a welder qualification is held by the individual, so a shop cannot lend one to another; if the welders who will run your job are not the ones named in the package, the package is not evidence for your parts.
Frequently Asked Questions
What is an essential variable?
A change that requires re-qualification rather than a paperwork update. The usual list includes the process, the material group, the thickness range, the welding position, the filler classification and, for procedures, the joint type and heat input range.
Does a certificate from another country count?
Generally yes if it is to the same standard, because ISO 9606 is internationally recognised. What matters is the scope and whether the employer has been confirming continued practice, which is the part that varies between systems.
Should I ask for the certificates before placing an order?
Ask for the scope relevant to your part rather than for every certificate the shop holds. A fabricator working to ISO 3834 will normally have a qualification matrix that maps procedures and welder scopes to the work they actually do, which is more useful than a folder of documents.
Questions about a specific part are usually faster to answer against the drawing — send it through the route below.
Practical next steps. Start with sheet metal welding service for the drawing review, read send the drawing for review for process context, and if you are choosing between routes, weld quality standards and inspection and welding inspection methods set out the alternatives side by side.