EN 10204 is the European standard that defines the types of inspection documents issued for metallic products. If you specify or receive material for industrial applications, understanding which document type is required — and what each guarantees — is fundamental to material qualification and regulatory compliance.
Quick Answer
Quick Answer
EN 10204 defines four document types. Type 3.1 is a mill inspection certificate signed by the manufacturer's authorised inspector. Type 3.2 adds co-signature from an independent third-party inspector. Type 3.2 is mandatory for critical applications such as pressure equipment, nuclear, and subsea.
Overview of EN 10204
First published by the European Committee for Standardisation (CEN) and widely adopted globally, EN 10204 establishes a tiered system for material inspection documentation. The 2004 revision (EN 10204:2004) is the current edition and defines four document types:
| Type | Name | Issued By | Specific to Product? |
|---|---|---|---|
| 2.1 | Declaration of Compliance | Manufacturer | No |
| 2.2 | Test Report | Manufacturer | No |
| 3.1 | Inspection Certificate | Manufacturer's authorised inspector | Yes |
| 3.2 | Inspection Certificate | Manufacturer + independent inspector | Yes |
Types 2.1 and 2.2 are based on non-specific inspection — they do not involve testing of the actual product delivered. Types 3.1 and 3.2 involve specific testing of the exact product batch and are the only types that qualify as a mill test certificate in most quality systems.
Type 2.1 — Declaration of Compliance
A Type 2.1 is the lightest form of documentation. The manufacturer simply declares that the supplied products comply with the requirements of the order, without providing any test data. No testing is performed on the specific delivery.
When used: Commodity products with low criticality requirements — fasteners, standard structural profiles for non-critical use, general-purpose flat products.
Limitation: Provides no actual test data and no product-specific verification. Not acceptable for pressure equipment, structural connections in safety-critical structures, or any application requiring traceable material properties.
Type 2.2 — Test Report
A Type 2.2 document includes test results, but those results come from non-specific inspection — tests performed on similar products from the same production process, not necessarily on the specific batch delivered.
When used: Low to medium criticality applications where the buyer requires some form of test data but the full traceability of a 3.1/3.2 certificate is not mandated by code or contract.
Limitation: Because the tests are not specific to the delivered batch, there is no direct link between the documented values and the material the buyer receives. A heat number is not required.
Type 3.1 — Inspection Certificate (Manufacturer's Authorised Inspector)
Type 3.1 is the standard mill test certificate used in the majority of industrial applications. Key characteristics:
- Tests are performed on the specific product being delivered
- Results are certified by the manufacturer's authorised inspector — a person employed by or contracted to the manufacturer, but whose quality function is independent of the production and sales departments
- The document is specific to the heat/cast number of the material delivered
- Both the specification compliance statement and the actual test values are included
What "authorised inspector" means: Under EN 10204, the person signing a 3.1 certificate must be independent of the production and sales departments within the manufacturer's organisation. This is an internal independence requirement, not third-party independence.
When required:
- Structural steel under EN 1090
- Pressure equipment under PED 2014/68/EU (most pressure boundary materials)
- Piping in oil and gas facilities per most client specifications
- Any application where the contract specifies EN 10204 3.1 without further qualification
Type 3.2 — Inspection Certificate (Manufacturer + Independent Inspector)
Type 3.2 is the highest level of EN 10204 certification. It builds on Type 3.1 by requiring that the inspection and certification be witnessed and co-signed by a representative independent of the manufacturer.
The independent representative is typically:
- An accredited third-party inspection body (TÜV, Bureau Veritas, DNV, SGS, Intertek, Lloyd's Register)
- The purchaser's own inspector (where the purchaser's representative is contractually defined as meeting the independence requirement)
- A regulatory body representative (in nuclear applications)
Both the mill's authorised inspector and the independent inspector must sign the certificate.
When required:
- Nuclear components (ASME Section III, RCC-M)
- High-pressure subsea equipment
- Projects where the client's quality plan explicitly mandates 3.2
- NORSOK M-650 qualified materials
- Any contract that specifies "third-party witnessed" material testing
3.1 vs 3.2: Side-by-Side Comparison
| Factor | Type 3.1 | Type 3.2 |
|---|---|---|
| Test specificity | Product-specific | Product-specific |
| Signatory 1 | Mill's authorised inspector | Mill's authorised inspector |
| Signatory 2 | Not required | Independent third party |
| Heat number traceability | Yes | Yes |
| Cost premium | Standard | 10–30% higher |
| Lead time impact | Minimal | Typically adds 2–5 days |
| Use case | Standard industrial | High-criticality, nuclear, subsea |
| Accepted for PED? | Yes (most categories) | Yes (all categories) |
How to Specify the Correct Certificate Type
The certificate type must be specified at the time of purchase order. Attempting to upgrade a 3.1 to a 3.2 after delivery is not possible — the independent inspector must be present during testing.
In a purchase order, specify:
Material documentation: EN 10204 Type [3.1 / 3.2] Inspection Certificate
For 3.2, additionally specify:
Third-party inspection body: [TÜV / Bureau Veritas / DNV / purchaser's representative]
Inspection notification: [X] working days before test
If your contract references another standard (e.g., ASME, API) alongside EN 10204, the more stringent requirement applies.
Common Mistakes When Handling EN 10204 Certificates
Accepting 3.1 when 3.2 is required. Always verify what the project specification or code requires before accepting material. A 3.1 certificate cannot be retrospectively upgraded.
Not checking the inspector's independence. For 3.1 certificates, confirm the signatory's department is genuinely independent of production and sales. Some non-compliant mills blur this boundary.
Confusing 2.2 with 3.1. At a glance, both contain test data. The key difference is specificity — a 2.2 may reference "typical" or "batch" data, not data from the specific delivery.
Accepting certificates with a missing or illegible signature. Both 3.1 and 3.2 require an original or certified electronic signature. An unsigned or illegible certificate does not meet the standard.
Not cross-referencing the heat number. The heat number on the certificate must match the marking on the physical material. This check is mandatory regardless of certificate type.
EN 10204 in Practice: Industry Applications
Oil and Gas
Most major oil company specifications (Shell DEP, ExxonMobil GP, Saudi Aramco SAES) default to EN 10204 Type 3.2 for pressure-containing parts and 3.1 for structural and non-pressure items.
Power Generation
Boiler and pressure vessel codes (ASME, EN 12952, EN 12953) typically require 3.1 as a minimum; nuclear applications require 3.2 or the equivalent under national nuclear codes.
Chemical and Process
The Pressure Equipment Directive 2014/68/EU requires specific inspection certificates for pressure-bearing materials in Categories II, III, and IV. EN 10204 3.1 satisfies most PED requirements; 3.2 is specified for the highest-risk equipment.
Structural Steel
EN 1090 (execution of steel structures) requires EN 10204 Type 3.1 as a minimum for structural steel. Type 3.2 is required for execution classes EXC3 and EXC4.
Frequently Asked Questions
Can a 3.1 certificate be upgraded to 3.2 after the material is delivered?
No. A 3.2 certificate requires an independent inspector to witness the actual testing at the mill. Once material has left the mill, this is not possible. The certificate type must be specified before manufacture.
Is EN 10204 applicable outside Europe?
Yes. While it is a European standard, EN 10204 is widely referenced globally — particularly in oil and gas, power generation, and petrochemical projects — because it provides a clear, internationally recognised framework for material certification levels.
What is the difference between product analysis and ladle analysis on an MTC?
Ladle analysis is taken from a sample of the molten metal before casting. Product analysis is taken from the finished product. Most specifications accept ladle analysis, but some require product (or cast) analysis for tighter control. The MTC should state which was performed.
Does EN 10204 apply to non-ferrous metals?
Yes. EN 10204 applies to all metallic products, including aluminium, copper alloys, titanium, and nickel alloys, not just steel. The same certificate type framework applies.
What should I do if I receive a 3.1 certificate when 3.2 was specified?
Issue a non-conformance report and reject the material or place it on hold. Contact the supplier immediately. The resolution options are limited — either the supplier provides the correct documentation (which may require re-testing with a third-party witness) or the material is replaced.
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