Welder certification according to DS/EN ISO 9606-1

When a company is certified under EN 1090 to manufacture load-bearing steel structures, it's not enough for the company as a whole to have procedures and controls in order. Each welder must themselves be able to document that they can properly perform the specific welding task. That's what certification under DS/EN ISO 9606-1 is about.

A weld bead can look nice on the surface even though it is weak inside. That is why standards such as EN 1090-2 require that welders working on load-bearing structures be qualified according to a recognized standard. DS/EN ISO 9606-1 covers the qualification of welders in fusion welding of steel and is the most common standard for hand welding in Denmark.

A certification is not just 'proof that you can weld'. It is tied to a number of concrete variables that together limit what the certificate covers. The certificate only applies within the combinations of variables it is issued for.

• 01Welding method (e.g. MMA, MIG/MAG, TIG)
• 02Material group (e.g. unalloyed steel stainless steel)
• 03Goods thickness and pipe diameter within the range covered by the sample
• 04Welding position (e.g. downhand, horizontal, vertical, overhead)
• 05Type of filler material and any shielding gas
• 06Joint type — for example butt weld or bevel weld

The welding test is supervised by a trained examiner who ensures the test is carried out according to the requirements of the standard. The welder performs an actual weld following an established welding procedure, and the result is assessed both visually and by one or more inspection methods — typically a destructive test where the test piece is bent or broken to reveal any internal defects, and often supplemented by non-destructive testing if the certificate is also to be used for pressure equipment.

A welder's certificate is not valid forever by itself. It requires the employer or a welding coordinator to confirm with a signature every six months that the welder has continued to weld within the certificate's range (point 9.2 of the draft of the new ISO 9606). On issue, one of three ways of extending it is also chosen (point 9.3 of the same draft): a) a new test every 3 years, b) every 2 years, when two welds from the last 6 months have been tested by radiography, ultrasound or destructive testing, or c) without an end date, as long as the welder works for the same company, the company's quality system has been verified according to ISO 3834-2 or -3, and it documents that the welder produces acceptable welds.

For the individual metal fabricator the certification system means competence is not just something you say you have — it is documented defined and time-limited. It gives customers and authorities a guarantee that the person who has welded a load-bearing structure has actually shown they can perform exactly that type of welding. At the same time it means a skilled welder must continually maintain their certificates if the work tasks change — for example if you start welding a new material group or a new position.