EN 10204 Certificates Explained: 2.1, 2.2, 3.1 and 3.2

The four document types

EN 10204:2004 is the European standard for the inspection documents delivered with metallic products. It defines four types, and the number is shorthand buyers and mills use worldwide:

Type	Name	Test basis	Who validates it
2.1	Declaration of compliance with the order	None — no test results	The manufacturer
2.2	Test report	Non-specific inspection	The manufacturer
3.1	Inspection certificate 3.1	Specific inspection	The manufacturer's inspection representative, independent of the production department
3.2	Inspection certificate 3.2	Specific inspection	As 3.1, plus the purchaser's representative or an inspector designated by official regulations

The key distinction: specific vs non-specific

Non-specific inspection means the tests were made on material produced by the same route and grade, but not necessarily on the items being delivered. The results are typical production data.

Specific inspection means sampling and testing were carried out on the products actually delivered — on their heat and lot. The results on the certificate belong to the material on the truck, and the heat number on the document matches the number stamped or stencilled on the product itself.

What each type actually proves

• 2.1 states only that the manufacturer declares the products comply with the order. It carries no results and is suitable only for low-criticality uses.
• 2.2 adds test results, but from routine production testing, not from the delivered heat. It cannot support a traceability claim: if the material is later questioned, a 2.2 does not prove what was shipped.
• 3.1 shows the actual chemistry and mechanical results of the delivered heat, validated by an inspector who is independent of the department that made the steel. This is the default document for certified construction, pressure parts and export projects.
• 3.2 adds a second, independent validation: the buyer's own representative or an officially designated third-party inspector witnessed the sampling and testing and countersigns. It closes the chain of trust between mill and end user.

When 3.2 is required

Specifications that call for 3.2 typically include pressure equipment in higher conformity categories, offshore structures, nuclear work, and the internal standards of major energy and process companies. Two practical points:

1. A 3.2 must be ordered before production. The witnessed sampling and countersignature cannot be created afterwards from existing paperwork.
2. It costs more and takes longer, because the inspector's attendance has to be scheduled into the mill's testing sequence.

Practical notes

• Name the document type in the purchase order. Writing "MTC required" alone leaves the type to mill practice, which may be 2.2.
• Check the certificate against the material: the heat numbers must match, and a 3.1 whose values are not heat-specific is not a 3.1.
• Certificates marked 3.1B use the terminology of the previous (1991) edition of EN 10204; 3.1B is the forerunner of today's 3.1.