How Do I Read a Mill Test Certificate? EN 10204 3.1 vs 2.2 Explained
How Do I Read a Mill Test Certificate? EN 10204 3.1 vs 2.2 Explained
Direct answer: EN 10204 3.1 is a certificate that carries actual test results - chemical composition and mechanical properties - and is issued by an inspection department independent of production. Type 2.2 is only a declaration of compliance and contains no test values. For export steel, 3.1 is the standard requirement because the numbers can be traced back to a specific heat.
| Type | Test results included | Issued by | Typical use |
|---|---|---|---|
| 2.1 | No | Manufacturer's production department | Non-critical stock, internal use |
| 2.2 | No | Independent inspection department of the manufacturer | General commercial supply |
| 3.1 | Yes | Manufacturer's authorised inspection representative | Steel export standard |
| 3.2 | Yes | Manufacturer plus an independent third party such as SGS | High-specification or regulated projects |
What a 3.1 certificate must show
A usable certificate carries the heat number, the chemical composition for each specified element, the mechanical results - yield strength, tensile strength and elongation - the coating weight where relevant, the dimensions, the governing standard and grade, and the signature and date of the authorised inspector.
The heat number is the linchpin. It is what links the paper to the physical coil, and it is the first thing to check when the certificate arrives.
How to spot a certificate that does not add up
Cross-check the heat number against the coil tag and the packing list. Confirm the standard and grade quoted match the PO, not a neighbouring grade. Check that every element falls inside the specification range for that grade - a certificate showing values comfortably mid-range across a dozen elements is more plausible than one sitting exactly on every limit.
Then sanity-check the mechanics against the grade. If the yield and tensile figures are identical to four decimal places across several different heats, the data has probably been templated rather than measured. Where the value of the order justifies it, a third-party check by SGS or BV closes the question.
Why 2.2 keeps appearing in quotations
Type 2.2 is cheaper and faster because no testing is performed for the document. It is legitimate for non-structural commercial supply, and it is not acceptable where a designer, a regulator or an end customer has specified 3.1. Ask which type is being quoted before comparing prices - a 2.2 quote and a 3.1 quote are not the same product.
