Iron & Steel
EN 10204 Mill Test Certificates Go Digital
EN 10204 certificate types (2.1, 2.2, 3.1, 3.2), the EN 10168 field list and how a PDF mill test certificate becomes signed, structured DPP batch data
Every steel shipment to the EU already travels with an inspection document: the certificate under EN 10204. Its content is exactly what belongs at the core of a batch passport: heat number, chemical analysis, mechanical test results, dimensions and standard. The problem is not the content but the format: the certificate is produced as a PDF, sometimes leaves as a scan and is re-keyed by hand on the receiving side.
This article covers the certificate types, the field list defined by EN 10168 and the path from PDF to signed, structured passport data.
EN 10204 certificate types
| Type | Document | Who confirms | Test data |
|---|---|---|---|
| 2.1 | Declaration of compliance with the order | Manufacturer | No results |
| 2.2 | Test report | Manufacturer | Non-specific inspection results |
| 3.1 | Inspection certificate | Manufacturer's authorised representative independent of production | Results specific to the products delivered |
| 3.2 | Inspection certificate | Manufacturer's representative and the purchaser's representative or an official inspector | Product-specific results, double confirmation |
The type is agreed in the order. For the passport: 2.1 and 2.2 are declarations, not evidence; 3.1 and 3.2 carry product-specific, independently confirmed test data. As evidence for the passport's chemical-analysis and mechanical-property fields, 3.1 or 3.2 is required.
The problem with PDF
A PDF certificate is readable by people, not by machines. The receiving service centre re-keys the heat number and analysis values by hand; every entry is a source of error and delay. Altered or forged certificates are a known risk in the metals trade, and the origin of a PDF is hard to verify. After several copies it becomes unclear which version is valid.
From the passport's point of view a PDF is unstructured evidence: it can be attached but not queried, compared or verified. See the DPP for iron and steel.
From EN 10168 to a structured schema
EN 10168 defines the information content of inspection documents for steel products and codes the fields in groups: commercial parties and order information, product description and dimensions, inspection results (tensile, impact, hardness, chemical composition), other tests and validation of the document. That coding is a ready-made skeleton for a data schema, and industry initiatives have already carried the same field list into JSON and XML schemas.
The mapping to the passport is direct:
- Heat number and product description go to the batch passport's identity fields.
- Chemical composition and mechanical results, with unit and test standard, go to the technical fields.
- Product standard and grade designation go to the grade field.
- Document type, confirming party and date go to the evidence metadata.
If the passport data model is JSON-LD based, the certificate fields can use the same vocabulary; see JSON-LD and DPP data and the data model guide. For the expected fields see steel DPP data fields.
Signing and verification
A structured certificate is an editable file until it is signed. The signing instrument for a company is the electronic seal: a qualified e-seal under eIDAS proves which legal entity issued the document and that it has not been altered since. The service centre verifies the seal, takes the data straight into its system and re-keys nothing. See eIDAS and e-seals.
On the passport side the same principle is met by EN 18246: the origin and integrity of passport data must be cryptographically verifiable. A sealed certificate is a ready input for that verification; see EN 18246 data authentication.
Attaching to the batch passport and integration
The certificate enters the batch passport in two forms: the structured fields populate the passport's technical section, and the sealed original is attached as evidence in the restricted tier. When a re-test or correction is needed, the passport is not overwritten; a new version is opened and the earlier certificate stays in the history.
The integration chain is short: the laboratory information system (LIMS) produces the analysis results, the ERP adds order and shipping information, and certificate and passport fields are derived from the same record. Where there is no second data entry there is no second source of error; see ERP integration for the DPP. For the link between heat number and passport identity see heat-number batch traceability.
For Turkish rolling mills selling to EU service centres this is more than a compliance step: a supplier offering machine-readable certificates removes the buyer's data-entry cost, and when the delegated act arrives the passport fields are already in place.
Frequently asked questions
What is the difference between EN 10204 3.1 and 3.2?
In 3.1 the results are confirmed by the manufacturer's authorised representative independent of production; in 3.2 the purchaser's representative or an official inspector confirms them as well. Both carry product-specific test data.
Is attaching the PDF certificate to the passport enough?
It can be attached as evidence, but the fields cannot be queried or machine-verified. A structured, sealed certificate populates the passport's technical fields directly.
Which format will my customer want for a digital certificate?
Most service centres accept a JSON or XML format based on the EN 10168 field list; writing the format and the seal requirement into the contract at order stage is the safest route.
