Mechanical Coupling Specification Example for Assembly Programmes: Budget Line
Mechanical Coupling Specification Example for Assembly Programmes: Budget Line
This is a worked specification for mechanical coupling in a budget line programme. It is the document we would send a buyer who asks what exactly they are getting: the material, the dimensions that are actually controlled, the finish, and the checks that happen before anything is packed.
The budget line version exists because the duty cycle on assembly programmes is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually a supplier who changed material without saying so.

Example specification
| Item | Mechanical Coupling |
|---|---|
| Application | Assembly Programmes |
| Version | Budget Line |
| Base material | Nylon 66 |
| Controlled dimensions | 5 key dimensions, recorded per lot |
| Tolerance band | ±0.5 mm |
| Finish | zinc plated |
| MOQ | 2,000 pieces per specification |
| Sampling | 14 working days, 5 days per revision |
| Compliance | ISO 9001 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Nylon 66, in this example.
- List the dimensions that are actually controlled and the tolerance on each.
- Name the finish and what it has to survive.
- State the inspection level and who pays when a lot fails.

Processes involved
- ultrasonic cleaning
- electroplating
- surface grinding
- injection moulding
- robot welding
- assembly line testing
Where this example applies
Programmes that run budget line most often specify this build for assembly programmes. Related applications include dealership service, workshop replacements, assembly programmes, trailer axles, utility trailers.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 2.5 sampling on the finished lot.
- Finish inspection under agreed lighting.
- Carton drop test on the first lot of a new packing specification.
Questions buyers ask
What happens if a lot fails inspection?
The lot is re-inspected against the golden sample, and replacement pieces ship on the next available booking at our cost.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the ISO 9001-compliant build instead of a fresh interpretation.
How is packing specified?
Individual packing, inner box quantity and carton marking are confirmed at quotation stage so the cartons arrive ready for your warehouse.
What testing is included?
Standard lots ship with dimensional and hardness reports. ISO 9001 documentation is issued with the shipment when your market requires it.
Send the part number, the annual volume and the target market, and we will come back with a specification and a sampling plan.



