Almost every overseas enquiry for pipes, flanges and fittings ends with the same line: "MTC as per EN 10204 3.1" — or, for critical projects, "3.2". Understanding EN 10204 3.1 vs 3.2 is not just paperwork. Choose wrong, and you either lose the order on price or face a rejected shipment at the buyer's warehouse.
This guide explains both certificate types, who signs them, what they cost and how to quote them correctly.
What EN 10204 actually is
EN 10204 is a European standard that defines the types of inspection documents a manufacturer can supply with metallic products. It does not tell you which tests to perform — the product standard (ASTM A312, ASTM A105, EN 10216 and so on) and the purchase order do that. EN 10204 only defines who confirms the results and how specific the testing is.
The current edition is EN 10204:2004. It lists four document types:
| Type | Name | Tests on | Validated by |
|---|---|---|---|
| 2.1 | Declaration of compliance | No test results | Manufacturer |
| 2.2 | Test report | Non-specific (same process) | Manufacturer |
| 3.1 | Inspection certificate | Specific (the actual lot) | Manufacturer's independent inspector |
| 3.2 | Inspection certificate | Specific (the actual lot) | Manufacturer's inspector and purchaser's or third-party inspector |
"Specific inspection" means tests are carried out on the products being supplied, or on test units from the same heat or lot. "Non-specific" means results come from the same production process but not necessarily from the items delivered.
EN 10204 3.1: the industry default
A 3.1 certificate is issued and signed by the manufacturer's authorised inspection representative, who must be independent of the manufacturing department — usually the QA/QC head. It confirms that:
- the products comply with the order and the product standard,
- the chemical and mechanical tests were done on the supplied lot,
- the heat number on the certificate matches the marking on the material.
Most stock pipes, fittings and flanges in the global market ship with 3.1 certificates. For general oil and gas, water, chemical and construction work, buyers accept them without extra cost.
EN 10204 3.2: when the buyer wants a second signature
A 3.2 certificate carries the same test data, but it is validated by two parties: the manufacturer's inspector and either the purchaser's authorised representative or an inspector named in official regulations. In practice that second signature usually comes from a third-party agency such as TÜV, Bureau Veritas, Lloyd's Register, DNV, SGS or Intertek.
The third-party inspector normally:
- witnesses sampling and marks test pieces,
- witnesses mechanical tests, PMI, hydro tests and dimensional checks,
- reviews the documents and stamps or co-signs the certificate.
Because the inspector must be present, a 3.2 order takes more time and more money. It also cannot be produced "after the fact" from stock that has already been tested — witnessing has to happen during testing. This is why stockists often cannot offer 3.2 on ready material.
When do buyers ask for 3.2?
Expect 3.2 requests in:
- offshore and upstream oil and gas projects,
- refineries, LNG and petrochemical EPC contracts,
- nuclear, power plant pressure parts and PED-regulated equipment,
- projects where the end client's specification demands it.
For distributors, maintenance stock and most MRO buyers, 3.1 is enough. If an enquiry says 3.2, ask which agency is acceptable and who pays for the inspector before you quote.
How to quote EN 10204 3.1 vs 3.2 correctly
Price the difference openly. A clean quotation line could read:
- Certification: EN 10204 3.1 included.
- Option: EN 10204 3.2 by TÜV / BV / LR — add USD X per lot, plus 7–10 days to delivery.
Third-party charges depend on the agency, city and number of visits, so many exporters quote inspection "at actuals". Our third-party inspection guide covers how to plan those visits without delaying dispatch.
If you prepare quotations often, QuoteMitra helps you build priced quotations with weights and terms, so certification lines are stated clearly in every quote.
What a good 3.1 or 3.2 certificate must show
Whichever type you issue, check that the certificate includes:
- certificate number, date and EN 10204 type clearly printed,
- purchase order number and item description,
- product standard and grade (for example ASTM A312 TP316L),
- size, quantity and heat number for every line,
- chemical composition and mechanical properties against specified limits,
- results of hydro, PMI, NDT, IGC or impact tests where required,
- name and signature of the authorised inspector (and the third party for 3.2).
Missing heat numbers or a mismatch between marking and certificate is the most common reason for rejection. Software such as MTCMitra builds certificates from a template so these fields are never forgotten.
Common mistakes exporters make
- Calling a 2.2 report a 3.1. If the tests were not done on the supplied lot, it is not 3.1.
- Re-typing mill data incorrectly. Traders often copy mill results into their own format. One typo in chemistry can trigger a complaint.
- Agreeing to 3.2 without naming the agency. Some end users accept only specific agencies. Clarify before the order is confirmed.
- Forgetting to add inspection time. A 3.2 witness visit needs booking. Build it into the delivery date.
Frequently asked questions
Is EN 10204 3.1 the same as a mill test certificate?
In everyday trade language, yes. "MTC" usually means an EN 10204 3.1 inspection certificate issued by the producing mill or the manufacturer.
Can a trader issue a 3.1 certificate?
A trader should supply the original manufacturer's certificate. If the trader carries out further processing, it can issue its own certificate for that stage while keeping traceability to the original heat.
Is 3.2 always better than 3.1?
Not better — just more independently verified. For most applications 3.1 is fully acceptable. Use 3.2 only when the specification or client requires it.
Does EN 10204 apply to ASTM materials?
Yes. EN 10204 defines document type only, so it is commonly used together with ASTM, ASME, API and EN material standards.
Key takeaways
- 3.1 is signed by the manufacturer's independent inspector; 3.2 adds a purchaser or third-party signature.
- Both require specific tests on the supplied lot.
- 3.2 costs more, takes longer and must be planned before testing.
- Always state the certificate type and inspection option clearly in your quotation.
Getting certification right the first time is one of the simplest ways to earn trust with overseas buyers — and to keep repeat orders coming.
