What the certificate must contain
A usable certificate of analysis includes the following:
- The name and grade of the material and its standard number, if any
- The lot or heat number and the production date
- The quantity and packaging covered by the certificate
- Chemical analysis results: the measured value and the specification limit for each element
- Physical properties where relevant: particle size distribution, moisture, density
- The analysis method used (XRF, ICP-OES, combustion analysis, and so on)
- The sampling method and the number of samples
- The name of the issuing body, the date, and an authorised signature or electronic approval
A certificate with no lot number cannot be tied to the material in front of you. Always check that the lot number on the certificate matches the packaging label.
EN 10204 document types
For metallurgical materials the type of certificate is defined by the EN 10204 standard. The difference lies in who issues the document and which lot the results belong to:
| Type | Name | What it means |
|---|---|---|
| 2.1 | Declaration of compliance | The producer declares that the material complies with the order. It contains no test results. |
| 2.2 | Test report | The producer reports test results based on non-specific inspection. The results may not belong to the lot shipped. |
| 3.1 | Inspection certificate | The results come from samples taken from the lot shipped. It is validated by the producer's authorised inspection department, independent of manufacturing. This is the type most commonly requested in industry. |
| 3.2 | Inspection certificate | Based on specific inspection as 3.1, and additionally validated by the buyer's authorised representative or an independent body. The highest level of assurance. |
In fields such as aerospace, energy and pressure equipment, 3.1 is generally the minimum requirement. State clearly in your order which type you want; requesting it afterwards usually means new samples and a new analysis.
How to check a certificate
- Confirm that the lot number matches the packaging label and the shipping documents.
- Compare the measured value of every element against the limit in your own specification, one by one; do not rely on the limit column printed on the certificate.
- Check whether any element in your specification is missing from the certificate. An element that is not reported has not been measured.
- Check that the analysis method suits the precision claimed; XRF may not be adequate for limits at ppm level.
- Check the date and the signature; do not accept an undated or unsigned document.
When independent testing is needed
The producer's certificate is enough in most cases. Verification at an independent laboratory is reasonable in the following situations:
- The first lot from a producer you are working with for the first time
- Applications where the end product is critical (aerospace, pressure vessels, medical)
- Specifications with impurity limits at ppm level
- Metals with a high unit value
- A non-conformity on an earlier lot
In those cases, sample testing is arranged at an independent third-party inspection body before loading. Having the sampling supervised matters as much as the analysis itself for the result to be valid.
Common problems
- Copy-and-paste certificates
- Certificates carrying identical values for different lots are suspect. In real analyses the values show small variations from lot to lot.
- Missing elements
- An element that has a limit in the specification but does not appear on the certificate means the material was accepted with no evidence of conformity.
- The wrong type
- Asking for 3.1 and receiving 2.2 is common. Check the type number printed on the document.
- Inconsistent lot information
- If the lot number on the certificate does not match the packaging label, ask the supplier before taking the material into stock.
Working with us
Every lot we supply arrives with a certificate of analysis. If you tick the EN 10204 3.1 inspection certificate or an independent test report in the quote form, whether they can be provided is stated separately in the quote and the cost is included in the price.
For questions about documents, write to sales@sourcinomatch.com.