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What EXC2 to EN 1090-2 actually requires from a supplier
Execution class is not a badge. It is a list of things that have to exist in the workshop before your weld is made, and a separate list of things it does not mean.
EN 1090-2 sorts the execution of steel structures into four classes, EXC1 to EXC4. The class is not chosen by the fabricator. It follows from the structure: its consequence class if it fails, whether it is loaded statically or in fatigue, and how it is made. Annex B of the standard walks through that choice. EXC2 is the ordinary case for most machine frames, conveyor structures, platforms and hoppers, and it is where the majority of contract weldments sit.
What the class actually obliges
EXC2 is a set of requirements that run through the whole job rather than a stamp applied at the end. In practice a supplier working to it has to be able to show you the following, on request, for your part.
- Welding coordination. A named, qualified welding coordinator with responsibility and authority defined to EN ISO 14731. At EXC2 this is not optional and it is not a job title someone holds in addition to running the shop floor.
- Qualified procedures. A welding procedure specification for each joint type in your part, written to EN ISO 15609-1 and backed by a procedure qualification record to EN ISO 15614-1 that actually covers your material group, your thickness and your position.
- Qualified welders. Welder qualification to EN ISO 9606-1, current, and covering the process and the range the part needs.
- Weld acceptance. Quality level C to EN ISO 5817 as the default for EXC2. Level B is what EXC3 asks for; a drawing can call for it at EXC2 and it will be priced as extra.
- Inspection. Visual inspection of every weld, plus supplementary non-destructive testing whose extent depends on the joint type and the class. What was tested and what was found is recorded.
- Traceability and tolerances. Material identified back to its inspection document, and dimensional acceptance against a declared tolerance class rather than against habit.
What EXC2 does not mean
This is the part that causes the most confusion in a procurement conversation, so it is worth being blunt. Working to execution class EXC2 is a statement about how a weldment is made. It is not CE marking, and it is not a declaration of performance.
CE marking of structural steelwork for construction works runs on EN 1090-1: the fabricator operates a factory production control system, a notified body assesses and certifies that system, and the fabricator then issues a declaration of performance for the product. A supplier can be entirely capable of EXC2 execution and still not hold an EN 1090-1 certificate, because the second is a separate assessment with a separate certificate number and a separate scope.
So the two questions are different questions. "Can you execute to EXC2?" asks about procedures, welders and inspection. "Can you CE mark this?" asks whether there is a notified body certificate and a declaration of performance behind it. Ask both, and do not accept an answer to the first as an answer to the second.
What to ask a supplier
- Which EN ISO 3834 level is your welding quality system certified to, by whom, and what does the certificate scope actually list?
- Who is your welding coordinator and what is their qualification?
- Do your procedure qualifications cover my material group and my thickness, or would a new one be needed?
- What inspection ships with the part, and in what form?
- If the part needs CE marking, do you hold an EN 1090-1 certificate, and what is its number?
Where we stand
Our welding quality system is certified to EN ISO 3834-2 by PQM, s.r.o., and EN 1090-2 is one of the product standards named in that certificate scope, alongside EN 12285-2, EN 14015, API 650, AWS D1.1 and AWS D1.3. The certified base materials are ISO/TR 15608 group 1 up to 40 mm and group 8 from 3.0 to 16.0 mm, welded MAG 135, manual and robotic. So we execute to EXC2 and to quality level C.
We do not hold an EN 1090-1 factory production control certificate and we do not issue a declaration of performance. If your structure needs CE marking under EN 1090-1, say so at enquiry: it changes who can supply it, and we would rather tell you at the start than at the end.