1 10 月, 2026
EN 10204 3.1 vs 3.2: Which Mill Test Certificate Do You Need?
Short answer: on EN 10204, a 3.1 certificate is issued by the steel mill’s own inspection department and reports the actual test results for the heat you receive, while a 3.2 certificate is the same document countersigned by an inspector who is independent of the mill. Most export steel orders ship with 3.1. Buyers specify 3.2 when their own project, their customer or a regulator insists on third-party verification. The EN 10204 3.1 vs 3.2 choice is about who signs the results, not about how much testing is done.
What EN 10204 actually covers
EN 10204 is the European standard for metallic products — types of inspection documents. It describes the documents a supplier may issue and what each one is allowed to state. It does not set the material properties: that is the job of the product standard, such as EN 10025 for structural steel, EN 10219 for cold-formed hollow sections, EN 10216 for seamless pressure pipe or GB/T 3091 for welded pipe.
The practical consequence is simple. Writing “EN 10204 3.1” into an enquiry does not raise or lower the grade — it tells the supplier which piece of paper must travel with the steel. A 3.1 certificate on the wrong grade is still the wrong grade. The certificate and the grade are specified separately, and both have to be right.
The four document types at a glance
| Document | Who issues it | What it states | Where you see it |
|---|---|---|---|
| 2.1 Declaration of compliance | The manufacturer | That the products comply with the order. No test results are reported. | Non-critical items and stock material where no traceability is required |
| 2.2 Test report | The manufacturer | Test results from the manufacturer’s own non-specific inspection — not necessarily the heat you bought. | General fabrication where the grade is checked but the heat does not have to be traced |
| 3.1 Inspection certificate 3.1 | The mill’s inspection department, independent of production | Specific results for the material delivered — chemical composition and mechanical properties tied to the heat or batch. | The normal document for exported steel; the one most buyers mean by “mill test certificate” |
| 3.2 Inspection certificate 3.2 | The mill, countersigned by an inspector independent of the mill | The same specific results, plus the signature of an inspector appointed by the purchaser or by an independent body. | Projects, regulated equipment and specifications that demand third-party sign-off |
3.1 vs 3.2: the difference in one sentence
The test data is the same; the signature is different. Under 3.1, the mill’s inspection department — a function that is separate from the production line — vouches for the results it tested. Under 3.2, someone outside the mill reviews those results and signs as well.
Two consequences buyers often miss:
- 3.2 does not mean more testing. It adds independent verification of the same tests. If you want additional testing — an impact test at a specified temperature, dimensional verification or non-destructive examination — that has to be written into the specification separately.
- 3.2 changes cost and lead time, not the steel. Scheduling an independent inspector takes time and adds a cost line, so it belongs in the offer and in the delivery plan from the start.
- Neither document makes the mill responsible for your design. The certificate records what was tested. Whether the material suits your application stays with your engineer.
Which one does your project need?
| Your situation | Document that usually fits | Why |
|---|---|---|
| General structural work, fabrication, distribution, resale | 3.1 | Standard export practice; the results are traceable to the heat without a third party in the chain. |
| Regulated equipment where a notified body or a national authority is involved | 3.2, or 3.1 plus an agreed independent inspection | The rules, not the supplier, decide when materials must be independently verified. |
| Your own quality procedure names a third-party inspector | 3.2 | The countersignature has to come from an inspector your procedure accepts. |
| Project with a contractual witness or hold point | 3.2 together with an agreed inspection plan | The document and the inspection activity are specified as a pair, so both have to be in the enquiry. |
| Commodity stock, non-critical use, no traceability requirement | 2.1 or 2.2, subject to your engineer’s approval | Lower cost and simpler paperwork, at the price of heat traceability. |
Five mistakes buyers make with certificates
- Treating “EN 10204 3.1” as a grade or a quality level. It is a document type; the grade is a separate line in the specification.
- Ordering 3.2 and expecting extra tests. You get an independent signature on the same results.
- Assuming one certificate covers a mixed container. A 3.1 certificate is specific to the heat and the lot it names, so a mixed load needs matching documents.
- Leaving the document requirement out of the enquiry and raising it after shipment. Adding it before the order is a line item; adding it after is a negotiation.
- Never reconciling the certificate with the packing list and the physical marks on the bundles. Certificate, marks and packing list must agree — that reconciliation is the buyer’s job.
What to put in your enquiry
- The product standard and the full grade designation, including the quality class letter.
- “EN 10204 3.1” or “EN 10204 3.2” as the document requirement, and for 3.2 the inspector or body that is acceptable to you.
- Whether the certificate must be available before shipment, and in what form.
- Any additional test or examination you want beyond the standard test programme.
- Any third-party inspection arrangement, including witness points and the inspection plan.
Related reading
- What does an EN 10204 3.1 certificate mean?
- How to read a mill test certificate
- How we inspect and certify each order
- Request a quotation
Frequently asked questions
What is the difference between EN 10204 3.1 and 3.2?
Both report the specific test results for the material delivered. A 3.1 certificate is issued by the manufacturer’s inspection department, which is independent of the production department. A 3.2 certificate is the same document countersigned by an inspector who is independent of the manufacturer — either appointed by the purchaser or supplied by an independent inspection body.
Is 3.1 or 3.2 better?
Neither describes better steel. 3.2 adds independent verification of the same results, so it costs more and takes longer. Specify 3.2 when your project, your customer or a regulation requires third-party sign-off, and 3.1 otherwise.
Can a trading company issue a 3.1 certificate?
No. An inspection certificate 3.1 is issued by the manufacturer. A trading company supplies the mill’s certificate with the shipment; it cannot issue that certificate in its own name.
Does a 3.1 certificate mean a third party tested the steel?
No. Under 3.1 the testing is done by the manufacturer, and the certificate is signed by the manufacturer’s inspection department rather than by production. An outside inspector signs only on a 3.2 certificate.
What is the difference between 2.2 and 3.1?
The 2.2 test report is based on the manufacturer’s non-specific inspection and does not have to relate to the particular heat you receive. The 3.1 certificate reports specific results for the material delivered, which is why it is the normal requirement for exported steel.
Does an EN 10204 certificate guarantee that the steel meets the grade?
It records the tests the mill carried out on that heat. Check the reported values against the requirements of the product standard, and check that the certificate, the bundle markings and the packing list all agree. The document is evidence; verification is still the buyer’s step.
Before you order, tell us the product standard, the grade and the inspection document you need — see the steel product catalogue, how we inspect and certify each order, or request a quotation.