On this page 9 sections
What is the difference between EN 10204 3.1 and 3.2 certificates?
Short answer
A 3.1 certificate is issued by the manufacturer and validated by its own authorised inspection representative, independent of production. A 3.2 certificate is additionally validated by the purchaser's inspector or a third-party inspector named in the order. 3.2 costs more and takes longer, so it is specified when the project requires independent witness.
Types of certificate
2.1 / 2.2: declarations of compliance without, or with non-specific, test results. 3.1: specific test results for the delivered product, validated by the manufacturer's independent inspection representative. This is the industry standard. 3.2: validated by both the manufacturer and the purchaser's representative or a third-party inspector, for critical service.
What an MTC should show
- Manufacturer, certificate number and date
- Specification(s), grade and edition
- Heat number and lot / piece identification
- Chemical analysis (heat and/or product)
- Tensile, hardness, impact and other tests
- Heat treatment and condition
- NDT and hydrostatic test results
- Dimensions and quantities
Review checklist
Match the heat number on the material to the MTC, check every value against the specification limits (not just "pass"), confirm supplementary tests ordered (IGC, impact, HIC), and verify dual certification if two specs are claimed. See also PMI testing.
What 2.1 and 2.2 mean
EN 10204 also defines type 2.1 (a declaration of compliance without test results) and 2.2 (non-specific test results). They are rarely acceptable for pressure equipment, where 3.1 is the usual minimum.
Planning a 3.2 order
Name the inspection agency on the purchase order, agree the inspection and test plan, and allow time for witnessing at the mill. See third-party inspection.
Related guides, comparisons and articles
Frequently asked questions
Is a 3.1 certificate the same as an MTC?
A 3.1 certificate is one type of mill test certificate. "MTC" is the general trade term.
Can a 3.1 certificate be upgraded to 3.2 later?
Only if the inspector can witness tests or verify retained samples, which is not always possible after delivery.
Is a 3.1 certificate enough?
For most industrial service, yes. 3.2 is specified where the purchaser or code requires independent witnessing.
Can inspection be witnessed by a third party?
Yes. Inspection by the buyer-nominated agency, with EN 10204 3.2 certification, can be arranged before dispatch.
Does Bright Tubes supply the materials in this guide?
Yes. The grades discussed and related products are supplied from stock or mill-sourced, with EN 10204 certificates.