Common problems with EN 10204 Material Certificates and how to avoid them
EN 10204 Material Certificates is a standard that defines the type of inspection document supplied with a material. It is used for proving that the material in the part is what the drawing called for. This entry explains what it is, what the numbers on a data sheet mean, and what to put on a drawing.
It is written from the point of view of the buyer and the drawing office: the values that are realistic in production, the ones that cost money, and the way the result is verified. Where an industry sets the requirement, semiconductor is used as the example: cleanliness and surface condition that matter more than the nominal size.
The problems that actually occur
These are the failures that show up on a real job, listed in the order in which they are usually discovered.
- Ordering 3.1 after the material has been cut, which is too late. The cause is usually upstream: a datum that is not the functional one, a fixture that does not repeat, or a specification that cannot be measured the way it is written.
- A certificate that does not carry the heat number, so it proves nothing. The cause is usually upstream: a datum that is not the functional one, a fixture that does not repeat, or a specification that cannot be measured the way it is written.
What causes them
In most cases the cause is upstream of the operation, not in it. Ordering 3.1 after the material has been cut, which is too late is usually a symptom of one of the three causes above rather than a problem in its own right.
How they are prevented
Prevention is duller than diagnosis. State the certificate type on the drawing and on the order, and the result is confirmed by the certificate is matched to the heat number on the material before the batch is released.
| Item | Note |
|---|---|
| Failure | ordering 3.1 after the material has been cut, which is too late |
| Prevention | state the certificate type on the drawing and on the order |
| Tolerance to hold | not applicable, this covers documentation |
| Finish to check | not applicable |
Applications
EN 10204 Material Certificates is used for proving that the material in the part is what the drawing called for, and in practice it appears most often in aerospace, medical, pressure equipment, offshore and structural work.
How it fits into a machining route
EN 10204 Material Certificates applies to the whole drawing rather than to one operation. It sets how the part is measured as much as how it is made, which is why it belongs on the drawing from the first issue and not in a note added after a query.The route is fixed before the first part is cut, and it is the route rather than the individual setting that holds the result: the premium the mill charges for a certified batch. Where a drawing calls for something the route cannot hold economically, that is raised at quotation rather than after the parts are made.
Standards, documentation and what is issued
The documentation requirement is EN 10204 with the type stated on the drawing. Material is supplied against a certificate where the application calls for it, inspection results are recorded with the job, and the records are kept so that a repeat order can be compared with the first instead of being measured from scratch.
The certificate is matched to the heat number on the material is the verification step. Where a customer format or a standard report is required, it is agreed before the batch starts, because a report written after the event is a report nobody can use.
Frequently asked questions
What tolerance should be specified for EN 10204 Material Certificates?
not applicable, this covers documentation is realistic in production. Tightening it beyond the functional requirement increases cost without improving the part.
Which material is usually used?
any is the usual choice, supplied against EN 10204 with the type stated on the drawing.
How is the result verified?
The certificate is matched to the heat number on the material, with the results recorded so a repeat order can be compared with the first.
What is the most common mistake?
A certificate that does not carry the heat number, so it proves nothing.
How long does it take and what does it cost?
A realistic cycle is an hour of administration, plus the material supplier's charge, and the cost driver is the premium the mill charges for a certified batch.
Related capability
If you are specifying EN 10204 Material Certificates on a drawing and want a second opinion on the route, send the model and the quantity. The first response is a manufacturability review with the likely risk points and a quotation, so the decision can be made on facts rather than on a price alone.
Machining, inspection and documentation are handled in one place, which is why the dimensional report and the material certificate arrive with the parts rather than after them.
Related entries
These entries sit next to EN 10204 Material Certificates in the encyclopedia: First Article Inspection, PPAP Submission, Deep Hole Drilling. Reading them together gives a fuller picture of how the process, the material and the measurement affect each other.
