Mill test certificate
Chemical composition and mechanical properties of the wire rod heat, issued by the mill — and traceable to the carton lot.
Quality & testing
Tested per lot, documented per carton.
A fastener fails in one of three ways: it breaks, it strips, or it rusts. Each of those has a test in our lab and a number on the certificate that ships with the lot — and each has a failure mode that a certificate does not catch if the sampling is wrong.
Test plan
What gets measured, and against what.
Frequency is per production lot unless your specification asks for tighter sampling. Test reports are issued in English and bundled with the mill certificate, not sent separately when someone remembers.
| Test | Standard | Frequency | Acceptance |
|---|---|---|---|
| Tensile strength | ISO 898-1 | Each lot | Class minimum, e.g. 800 MPa for 8.8 |
| Proof load | ISO 898-2 | Each lot (nuts) | No stripping or thread deformation |
| Hardness | ISO 6508 / ISO 6507 | Each heat-treat basket | Within class range; 12.9 checked for decarburisation |
| Dimensions & thread | ISO 1502 · go/no-go | Each lot, AQL 1.0 | 6g external / 6H internal |
| Coating thickness | ISO 2178 / ISO 1461 | Each plating batch | Per finish specification |
| Neutral salt spray | ASTM B117 | Monthly per finish | Hours per the agreed class |
| Hydrogen embrittlement | ISO 15330 | Class 10.9+ plated parts | No failure after 24 h under load |
Salt spray is the one test that cannot run inside a 15-day lead time. It is sampled monthly per finish; if your specification needs a per-lot 480 h result, the lead time becomes 25 days and we quote it that way rather than promising both.
Traceability
From heat number to your receiving bay.
Every carton label carries the lot number, and the lot number resolves to a heat number, a heading machine, a heat-treat basket and a plating batch. If a question comes back six months later — or in a recall — the answer is on file, not reconstructed.
- Mill certificate EN 10204 3.1 for the wire rod
- In-process SPC on head height and thread pitch diameter
- Final inspection report with the lot number printed on it
- Retained samples kept for 24 months
- 01Wire rod
Heat no. recorded on receipt
- 02Heading
Machine and die ID on the route card
- 03Heat treatment
Basket and hardness survey
- 04Plating
Batch, thickness and salt-spray coupon
- 05Final inspection
Dimensions, thread, tensile
- 06Carton
Lot no. printed on the label
Documents
Paperwork that comes with the parts.
Property class test report
Tensile, proof load and hardness results for the production lot.
Quality management certificate
Scope and certificate number supplied as a PDF with the first order.
Declaration of conformity
Coating and material declarations, signed per shipment where required.
First article inspection
Full dimensional report with ballooned drawing, level 3 on request.
Commercial documents
Packing list, invoice, origin declaration and HS 7318 for customs.
Audit questions
What a receiving inspector asks.
If you need a number we have not published, ask — we would rather send a report than a reassurance.
Is every lot tested, or only sampled?
Mechanical properties and dimensions are tested per production lot; salt spray runs monthly per finish because 480 hours cannot fit inside a 15-day lead time. If your specification needs per-lot salt spray, it becomes a 25-day lead time and we quote it that way.
What sampling do you use?
ISO 2859-1, generally AQL 1.0 on dimensions and thread, with 100% optical sorting upstream. Automotive programs get 100% sorting on the characteristics we can measure in line.
How long do you keep records and samples?
Retained samples and inspection records for 24 months as standard. Longer retention is quoted where a customer’s own procedure requires it — 15 years is common in automotive.
Can I audit the plant?
Yes, by appointment, and we would rather you did it before the first order than after. A line walk plus a lab review takes about half a day; we will send the process flow and control plan in advance.
Audit
Want to see the inspection report before you order?
Ask for a sample lot report for the SKU you are considering. It is the same document that would ship with your order — not a marketing datasheet.