Certificates 3.1 and 2.2 to DIN EN 10204
The inspection certificate 3.1 to DIN EN 10204, in purchasing usually called a mill certificate 3.1, uses the results of specific inspection on the delivered product to prove that the order has been fulfilled. It is issued by the manufacturer's inspection representative, who is independent of manufacturing. With test report 2.2, by contrast, the manufacturer confirms compliance itself, based on the results of non-specific inspection.
Mark Waldhoff
Managing Director
Short answer
- DIN EN 10204 defines four types of inspection document: 2.1, 2.2, 3.1 and 3.2.
- Type 3.1 is based on specific inspection of the delivered goods or of parts of them, type 2.2 on inspections of products of the same kind.
- With 3.1, an inspection representative of the manufacturer who is independent of manufacturing confirms the results, with 3.2 a representative of the purchaser or of the authority confirms them as well.
- Distributors may only pass on inspection documents unchanged, apart from the quantity.
- For fasteners, DIN EN ISO 16228 is a separate standard with the types F2.1, F2.2, F3.1 and F3.2.
The abbreviations 2.2 and 3.1 stand for two different kinds of proof. They differ in what was inspected and who confirms the results. Which one you need depends on your component and is specified in the order.
This article reflects the status as of 26 September 2026. The applicable version is DIN EN 10204:2005-01, the German version of EN 10204:2004. A revision is under way at European level.
What DIN EN 10204 covers
DIN EN 10204 specifies which types of inspection document a purchaser can receive with the delivery of metallic products. It does not make any of them mandatory. Which document accompanies the delivery is agreed in your order.
What matters is how far the statement goes. An inspection document confirms that the inspected characteristics comply with the order. It is not a general quality guarantee for the entire product.
The four inspection documents compared
The standard defines four types. The manufacturer confirms the two documents of the 2 series itself, while an inspection representative signs the inspection certificates 3.1 and 3.2.
| Type | Designation | What is confirmed | Confirmed by |
|---|---|---|---|
| 2.1 | Declaration of compliance with the order | Compliance with the order, without test results | Manufacturer |
| 2.2 | Test report | Compliance with the order, with results of non-specific inspection | Manufacturer |
| 3.1 | Inspection certificate 3.1 | Compliance with the order, with results of specific inspection | inspection representative of the manufacturer, independent of manufacturing |
| 3.2 | Inspection certificate 3.2 | as 3.1 | inspection representative of the manufacturer and inspection representative of the purchaser, or the inspection representative designated in official regulations |
Source: EN 10204:2004, summarised from Wikipedia (EN 10204) and VOREST AG, accessed on 26 September 2026.
So only 2.2, 3.1 and 3.2 contain test results. The declaration of compliance 2.1 merely confirms that the order has been fulfilled.
Difference between test report 2.2 and certificate 3.1
Test report 2.2 shows test results from products of the same kind, inspection certificate 3.1 shows results from the delivered goods themselves. In addition, with 2.2 the manufacturer confirms, with 3.1 an inspection representative who is independent of manufacturing.
Specific and non-specific inspection
With test report 2.2, the results come from non-specific inspection. The products inspected were manufactured to the same specification and by the same process. They do not have to be the goods that arrive at your site, which is why the report usually contains statistical values from the manufacturer.
Inspection certificate 3.1 is different. Here the inspection is specific, carried out on the products to be supplied or on parts of them, for example on the coil from which the sheets were cut. The test results must be stated as figures in the certificate, and it must be possible to trace the delivery back to them.
Who confirms
Test report 2.2 is confirmed by the manufacturer. Inspection certificate 3.1 is signed by an inspection representative of the manufacturer who is independent of the manufacturing department. Type 3.2 requires two signatures: that of the manufacturer's inspection representative and that of a representative of the purchaser or of the authority.
Is it a mill certificate 3.1 or an inspection certificate 3.1?
The correct term is inspection certificate 3.1, because the standard only uses the term Werkszeugnis (test report) for type 2.2. In purchasing, mill certificate 3.1 (Werkszeugnis 3.1) has nevertheless stuck, and it almost always refers to the inspection certificate.
Older designations are also still in circulation. The 2004 edition deleted the specific test report 2.3 and the variants 3.1 A and 3.1 C. Today's 3.1 corresponds to the former 3.1 B. Acceptance inspections that used to fall under 3.1 A or 3.1 C are now covered by 3.2.
That is why you should write the full designation in the order, for example inspection certificate 3.1 to DIN EN 10204:2004. This prevents any misunderstanding about what was meant.
What applies to screws and fasteners?
Finished fasteners have a standard of their own, DIN EN ISO 16228, 2018-05 edition. It applies to screws, nuts, washers, pins, rivets and similar parts, whether made of steel, stainless steel, non-ferrous metals or non-metallic materials.
The types there are called F2.1 (declaration of compliance) and F2.2, F3.1 and F3.2 (reports and certificates). They can be issued by the manufacturer or distributor of the fasteners or by an external authorised representative, namely when the purchaser requests them with the order. The standard is precise about terms. In the German version, it requires Zeugnis or Bescheinigung, not Zertifikat.
DIN EN ISO 16228 is not intended for special purposes or specially developed parts that require other procedures such as initial sampling. There, an initial sample inspection report is part of the proof.
What distributors may pass on
According to EN 10204, distributors pass on inspection documents only as an original or a copy, without changing the content. The only permitted change is adjusting the quantity. Anyone passing on copies must use a procedure that ensures traceability.
This does not have to be done on paper. EN 10204:2004 expressly permits inspection documents to be transmitted and stored electronically.
When which document makes sense
The more safety and traceability depend on it, the more likely you are to end up with 3.1 or 3.2. This is what common practice looks like:
| Requirement | Usual choice |
|---|---|
| Catalogue part, proof of identity is sufficient | 2.1 |
| Standard part, typical material values from the manufacturer are sufficient | 2.2 |
| Part made to drawing, safety-relevant part, traceability to the batch required | 3.1 |
| Acceptance by the customer, an expert or an authority is mandatory | 3.2 |
At the end of the day, what is binding is what the order, drawing and product standard require. The table does not replace that check.
How NORM+DREH handles this: Depending on the product, NORM+DREH supplies material certificates and inspection reports with the delivery. Which inspection document belongs to your component follows from your drawing and the standard, and we record it in the quotation. Before goods go into our warehouse, our own quality department in Velbert inspects every incoming delivery. We are certified to DIN EN ISO 9001 and DIN EN ISO 14001. Send us your drawing or existing inquiry and we will be glad to clarify which documentation is required. More on this on the page Quality and inspection certificates.
Frequently asked questions about inspection certificate 3.1
What is a mill certificate 3.1?
In purchasing, this usually means the inspection certificate 3.1 to DIN EN 10204. It uses the results of specific inspection on the delivered goods to prove that the order has been fulfilled. It is signed by the manufacturer's inspection representative, who is independent of manufacturing.
What is the difference between test report 2.2 and certificate 3.1?
Type 2.2 contains results of non-specific inspection on products of the same kind and is confirmed by the manufacturer. Type 3.1 contains results of specific inspection on the delivered goods, confirmed by an independent inspection representative.
Who may issue an inspection certificate 3.1?
The manufacturer's inspection representative, who is independent of the manufacturing department. Distributors only pass on the certificate unchanged and may only adjust the quantity.
Is DIN EN 10204 still current?
Yes. As of 26 September 2026, DIN EN 10204:2005-01 applies, the German version of EN 10204:2004, and a revision is under way at European level. For fasteners, DIN EN ISO 16228:2018-05 is a separate standard.