Material certificates 3.1 and 3.2 to EN 10204

Every delivery of steel, stainless steel or welding consumables should come with a document showing what has been supplied. EN 10204 defines the types of inspection document: 2.1, 2.2, 3.1 and 3.2. The 3.1 certificate is the most commonly requested document in steel construction and equipment manufacturing, while the 3.2 certificate is mainly found in pressure equipment, offshore work and projects with independent inspection.

Things still go wrong regularly: a certificate that does not match the delivery, a 2.2 where a 3.1 was required, or a heat number that disappears once the material is cut. This article explains what each type means, who signs it, when to require which type and how to maintain traceability.

1. The four types of inspection document in EN 10204

EN 10204 distinguishes between non-specific and specific inspection. With non-specific inspection, results come from regular production and not necessarily from the batch delivered. With specific inspection, testing is carried out on the products supplied or on the test unit they come from.

• Type 2.1, declaration of compliance: the manufacturer declares the products comply with the order, without test results.
• Type 2.2, test report: the same declaration, with results of non-specific inspection.
• Type 3.1, inspection certificate: the manufacturer declares compliance with the order and states the results of specific inspection.
• Type 3.2, inspection certificate: as 3.1, but co-signed by an independent party.

Only 3.1 and 3.2 therefore say anything about the material actually on your shop floor.

2. Who signs a 3.1 and a 3.2 certificate

The difference between 3.1 and 3.2 lies not in the measurements but in who confirms them. A 3.1 certificate is validated by the manufacturer's authorised inspection representative, who must be independent of the manufacturing department, in practice the quality department of the mill or producer.

A 3.2 certificate is prepared by that representative together with an external party: the purchaser's authorised inspection representative or an inspector designated by the official regulations. Think of a classification society, a notified body or an inspection agency engaged by the client. That party is involved in the testing and co-signs. A 3.2 must therefore be requested with the order; it cannot be produced afterwards.

3. When to require which material certificate

The type required follows from the applicable standard or regulations and the client's specification:

• Steel structures under EN 1090-2: the standard sets the minimum inspection document per product type. For structural steel a 3.1 certificate is the usual baseline, although a 2.2 is allowed in certain cases depending on grade and class. Always check the current table and any additional requirements, particularly for EXC3 and EXC4.
• Pressure equipment under PED 2014/68/EU: materials for main pressure-bearing parts in categories II, III and IV require a certificate of specific product control, in practice a 3.1. Where the material manufacturer has an appropriate quality system certified by a competent body in the EU with a specific assessment for materials, its certificate is presumed to demonstrate conformity.
• Offshore, shipbuilding and critical installations: specifications often require 3.2, with a classification society or designated inspection body as co-signatory.

Do not require a 3.2 by default where a 3.1 suffices. It adds cost and lead time without changing the steel.

4. What to check on a certificate

Receiving a certificate is not the same as checking it. At goods-in, check at least:

• Document type: does it really say 3.1 or 3.2, and has the right party signed?
• Standard and grade: do they match the order and drawing, including subgrade such as J2 or K2?
• Dimensions and heat number: do they match the marking on the material itself?
• Chemical composition and mechanical properties: within the product standard, with impact tests at the correct temperature?
• Additional specification requirements, such as ultrasonic testing of plate or through-thickness properties.

If anything does not match, quarantine the material as non-conforming and do not use it until the issue is resolved.

5. Material traceability through the workshop

A certificate only has value if you can show it belongs to the component that was built in. EN 1090-2 requires material to be traceable from receipt to handover, with stricter identification and marking requirements for EXC3 and EXC4. Batch-level traceability is often allowed unless the specification requires traceability per component.

In practice this means:

• The heat number or an internal code is transferred to every offcut before cutting.
• Work preparation links part numbers to certificates, for example in a material list or weld map.
• When buying from stockholders, require the producer's certificate to be supplied.
• The result goes into the quality dossier, showing per component which material was used.

For load-bearing steel structures this also underpins CE marking. For independent review of goods-in inspection or the dossier, see welding inspection and QA/QC.