The four documents, and what each one actually proves
Certificate of conformity (CoC). A statement from the supplier that the parts conform to the drawing. Its value is entirely in the detail. A CoC that names the part number, the drawing revision, the quantity, the order number and the material batch is useful. A CoC that says the parts are to specification proves nothing.
EN 10204 3.1 material certificate. Issued by the material manufacturer, showing actual chemical composition and mechanical test results for the specific cast or heat, validated by the manufacturer's own authorised inspection representative. This is the standard requirement for pressure, structural and safety-critical work.
EN 10204 2.2 or 2.1. A 2.1 is a statement of compliance with no test results. A 2.2 includes test results, but from non-specific inspection, meaning the results are not tied to your batch. If your QA team asked for a 3.1 and you were sent a 2.2, you do not have traceability to your material.
EN 10204 3.2. Same as a 3.1, but countersigned by an independent inspector or the buyer's representative. Rarely needed outside regulated sectors, and it costs both time and money.
First article inspection report (FAIR). A dimensional report covering every characteristic on the drawing, usually to AS9102 in aerospace. This is what proves the process was right at the start, and it is the reference point when a later batch drifts.
The chain that matters runs cast number, to material certificate, to job number, to inspection record, to your delivery note. If any link is missing, you cannot answer a customer audit question about which material went into which part.
Where the paperwork goes wrong
The wrong drawing revision was built. The most expensive documentation failure there is, and the cheapest to prevent. Require the CoC to state the revision built, and check it against the revision you released.
The certificate is generic. A mill certificate for the grade rather than for your cast. Common when material comes from stock with the traceability broken at the merchant.
Certificates arrive weeks after the parts. Your goods-in is blocked, or worse, the parts get used and the paperwork gap surfaces during an audit.
The 8D is superficial. Corrective action responses that name operator error as the root cause and promise retraining. That is a symptom, not a cause. A real 8D explains why the process permitted the defect and why the inspection did not detect it.
Certification was not requested at RFQ stage. This is the one that hurts. Once the material has been cut from untraced stock, no amount of goodwill produces a 3.1 certificate afterwards.
What to specify, by application
| Application | Minimum documentation | Why |
|---|---|---|
| General machined part, non-critical | Certificate of conformity naming the drawing revision | Establishes what was actually built |
| Structural, pressure or load-bearing | CoC plus EN 10204 3.1 material certificate | Ties actual test results to your cast |
| New part or first production run | Add a dimensional inspection report against the drawing | Baseline for detecting later drift |
| Aerospace or defence | AS9100 supply chain, FAIR to AS9102, full traceability | Sector requirement, not optional |
| Medical | ISO 13485 supply chain, validation and change control | Regulatory requirement |
| Nuclear or energy | Material certs, welding qualification records, NDT reports | Sector requirement, and audited |
| Coated or plated parts | Add the coating certificate and thickness records | The finish is a process with its own conformity evidence |
How to make sure the paperwork actually arrives
Put the requirement in the RFQ, not in the purchase order. Certification changes the material source and therefore the price, so a requirement introduced after quoting produces a requote or an argument. How that plays into quote turnaround is covered in its own guide.
Name the exact standard. "Material certificate" is ambiguous. "EN 10204 3.1" is not.
Make documentation a condition of delivery. If the paperwork is part of the deliverable, it arrives with the parts. If it is an afterthought, it arrives when someone chases.
State who signs the CoC and require the drawing revision on its face.
Ask for it digitally, packaged per despatch. A PDF pack per delivery note is easier to file, easier to retrieve at audit, and impossible to lose in a van.
What this looks like in practice
A material traceability pack ships with every TrueNorth order as standard rather than as an extra. That is a deliberate part of the offer, because the buyer's real exposure is not the part, it is being unable to answer their own customer's audit question.
On a hydrogen sector enquiry for long tie rods, over two metres and around 103 kg each, two questions decided the whole route. Whether the material certificate had to be 3.1, and whether the threads were gauged after coating rather than before. Both were settled before quoting rather than after production.
On a square flange that failed inspection for chipping, a surface finish below the drawing requirement of Ra 0.8, and tool wander, the documentation trail is what made the response fast. The non-conformance report, the disposition and the corrective action request all referenced the same job and material records, so the replacement route was agreed in days rather than argued for weeks. The drift itself is covered in the batch consistency guide.
TrueNorth is working through ISO 9001 accreditation, and the traceability structure was built to that standard from the start rather than retro-fitted.