ISO 9606-1 welding certificate for EN 1090: welder qualification

A welder certificate under ISO 9606-1 proves that a welder can control a specific welding process, material and welding position. For steel, this is the standard you need for EN 1090 and the ISO 3834 chain. According to Kiwa , qualified welders under ISO 9606 are a condition for EN 1090 certification.

The certificate belongs to the person, not to the company. The company makes sure the welder works within their qualification and that the validity is kept up to date. In practice, that last part is the biggest concern. The FPC system therefore includes a register of all welders.

Short answer: a welder may only work within the qualification on their certificate. If the certificate expires, or a welding position falls outside its range, they may not make that weld, even if they did so before.

What does a welder certificate contain?

A welder certificate is a document with a set of fixed fields. The exact layout differs per certifying body, but the content is the same. This is a fictional example of one line from a welder matrix:

Field	Example
Welder name	J. de Vries
Designation	ISO 9606-1 135 P FW FM1 S t10 PB
Welding process	135 (MAG, solid wire)
Base material	Steel, group 1.2 (fictional)
Thickness and diameter	Range as stated on the certificate
Welding position	PA, PB (ISO 6947)
Issued by	Certifying body, with number
Valid until	Date, as stated on the certificate

The designation on the certificate says a lot. It states the process (135), the product type (P is plate), the type of weld (FW is fillet weld), the filler metal group (FM1), the thickness (t10) and the welding position (PB). The structure follows the standard, and the values in this example are fictional. A welder qualified for PA (flat) is not automatically qualified for overhead welding. So always check that the position you need appears on the certificate.

Why steel and aluminium have different certificates

For steel you use ISO 9606-1. For aluminium, ISO 9606-2 applies, see EN 1090-3 for aluminium. A welder who handles steel well is therefore not qualified for aluminium. The ISO 3834 page explains which standard belongs to which material. If you work with both materials, you need both certificates.

Validity and renewal

A welder certificate is not valid forever. Clause 9 of the standard sets how long it remains valid, how the employer or welding coordinator periodically confirms that the welder works within their qualification, and how the certificate is renewed.

We do not state fixed periods here, because sources explain them differently. Check the periods in the standard or with your certifying body, and enter every expiry date and confirmation date in your matrix.

The most common problem at an audit is an expired welder certificate. A welder who keeps working after the expiry date creates a deviation that you cannot fix with an excuse.

How do you build a welder matrix?

A welder matrix is an overview of all your welders, their certificates and their expiry dates. It belongs to the FPC system and to the WPSs. The matrix shows at a glance who is allowed to do what.

Collect all certificates

Ask each welder for the original certificate. Copies without a date are not usable.

Note the process, material and position for each welder

Put the welding process, the material and the welding positions in separate columns. This shows immediately which WPS a welder may carry out.

Put the expiry date in a calendar

Set a reminder well before the expiry date. Plan the renewal before the welder has to weld again.

Link the welder to the work order

Record which welder made a weld. This lets you prove the qualification for that weld afterwards, which also belongs to traceability.

What does the auditor check?

The notified body usually checks a sample of welders. It asks the welder for the original certificate and checks whether it matches the work the welder did. It also asks about the confirmations and about who maintains the matrix.

A well-prepared company has three things ready: the current matrix, the original certificates and an overview of the welds each welder made in the period. If one of the three is missing, there is often a finding.

Common mistakes

Certificate in someone else’s name. A welder who comes from another employer has a certificate from that body. You must have it checked yourself, not rely on a copy.

Forgetting the position. A welder with a certificate for PA may not simply weld overhead. This is a subtle mistake that often only comes up in a sample check.

Matrix not updated. A matrix that has not been completed for half a year is worse than no matrix. It shows that your system does not work.

Welder switching processes. A welder who moves from MAG to TIG needs a new qualification for TIG.

Frequently asked questions about welder certificates

Is the certificate held by the welder or by the company?

The certificate belongs to the person. The company is responsible for making sure the person works within their qualification and that the validity is kept up to date.

May a welder work with an expired certificate?

No. After the expiry date, the welder may not weld until the qualification has been renewed or extended. Stop the work and arrange the renewal.

Which welder may use which WPS?

A welder must be qualified for the process and position of the WPS they use. The WPS and the welder qualification go together. See the page on the WPS for the connection.

What is the difference from a welding diploma from a training course?

A welding diploma can be useful proof of training. For EN 1090, the certificate under the ISO standard, issued by a recognised body, counts. A diploma does not replace it.