GUIDE
EN 10204 material certificates: 2.1, 2.2, 3.1 or 3.2?
Everyone asks for "a 3.1" without always knowing what the number commits to. The standard defines four documents, only two of which carry test results on the product actually delivered.
What the standard actually distinguishes
Two notions structure EN 10204, and confusing them is the fundamental error.
Non-specific inspection: testing is carried out on products made by the same process, not necessarily on those you receive. The document attests that production is compliant in general.
Specific inspection: testing is carried out on the product delivered, or on the inspection unit it comes from — typically the heat. The document traces your material.
Types 2.1 and 2.2 belong to the first, types 3.1 and 3.2 to the second. That is the only boundary that matters.
The four types
2.1 — Declaration of compliance with the order. The manufacturer declares the product compliant. No test results are given. Sufficient for structural products with no traceability requirement.
2.2 — Test report. The manufacturer supplies non-specific test results from its routine production. The document contains figures, which is why it is often mistaken for a 3.1 — but those figures do not relate to your batch.
3.1 — Inspection certificate. Test results specific to the product delivered, validated by a representative of the manufacturer's inspection function independent of the production department. That internal independence is what gives the document its value. It carries the heat chemistry, the mechanical properties, the tests required by the product standard, the heat number and the batch identification. It is the industry standard, and the one SPS supplies with the goods.
3.2 — Inspection certificate with third party. Same content, additionally validated by an inspector appointed by the customer or by a body designated in regulation. It requires an intervention to be arranged in advance — sometimes attendance at the mill while testing takes place.
Why 3.1 is almost always enough
A 3.1 carries the two pieces of information specifications are really after.
The heat chemistry. It is what the actual PREN of your material is calculated from, rather than the grade's range. On a borderline application in chlorinated media that difference is decisive: a heat of 2507 may show 41 or 44 depending on where it sits in the ranges.
The heat identification. It is the entry point for all later traceability, including for expert analysis after an incident.
A 3.2 adds no information about the material: it adds an outside view of the inspection process. Its value is contractual and regulatory, not technical.
When a 3.2 is genuinely required
On certain pressure equipment, depending on the risk category and the conformity assessment module. In certain project specifications, notably in nuclear, offshore and parts of heavy chemicals. And where the customer imposes its own inspector at the mill.
In all these cases the requirement is known at tender stage. It must appear there: a 3.2 is prepared with the source, it is not produced after delivery. A batch delivered without the required document cannot be accepted, and no retrospective fix is possible — a specific test validated by a third party cannot be redone on tube already shipped.
Comparison
| Criterion | 2.1 | 2.2 | 3.1 | 3.2 |
|---|---|---|---|---|
| Type of inspection | non-specific | non-specific | specific | specific |
| Test results | none | yes, other production | yes, product delivered | yes, product delivered |
| Validated by | manufacturer | manufacturer | inspection independent of production | + third party |
| Heat chemistry | no | no | yes | yes |
| Traceability of your batch | no | no | yes | yes |
| Must be requested upfront | no | no | no | yes |
What the certificate does not tell you
A certificate attests compliance with a product standard. It does not say whether the grade suits your medium, or whether the wall thickness suits your pressure. A perfectly certified tube can be entirely wrong for its service.
Nor does it cover origin. Melt & Pour traceability — the country where the steel was melted and poured — is separate information, now demandable on import and one your customs agent will ask for. It is requested explicitly, in the same way as the certificate.
Frequently asked questions
- What is the difference between a 2.2 and a 3.1?
- A 2.2 gives test results that do not relate to your batch. A 3.1 gives those of your heat, validated by an inspection function independent of production. Both contain figures; only one concerns you.
- Can a distributor issue a 3.1 certificate?
- The original certificate is issued by the manufacturer. A distributor passes that document on and may add a declaration of conformity for its own batch, without standing in for the producer. Ask to see the manufacturer's certificate.
- Is Melt & Pour the same as a certificate of origin?
- No. Melt & Pour identifies where the steel was melted and poured, which is more precise than customs origin — a product may be processed in one country and poured in another. Request it explicitly.
- How long should these documents be kept?
- At least the life of the installation, and longer where regulatory or insurance obligations apply. In an investigation after a failure, the absence of a certificate makes any adversarial analysis impossible.