Mechanical Coupling Specification Example for Courier Fleets: Heavy Duty
Mechanical Coupling Specification Example for Courier Fleets: Heavy Duty
This is a worked specification for mechanical coupling in a heavy duty 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 heavy duty version exists because the duty cycle on courier fleets 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 | Courier Fleets |
| Version | Heavy Duty |
| Base material | Carbon Steel |
| Controlled dimensions | 6 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | painted |
| MOQ | 200 pieces per specification |
| Sampling | 10 working days, 3 days per revision |
| Compliance | SAE J431 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Carbon Steel, 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
- injection moulding
- sintering
- surface grinding
- shot blasting
- precision stamping
- laser cutting
Where this example applies
Programmes that run heavy duty most often specify this build for courier fleets. Related applications include trailer axles, boat trailers, utility trailers, light trucks, passenger cars.
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
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the SAE J431-compliant build instead of a fresh interpretation.
Can you match an existing sample?
Send a sample and we will reverse-engineer the specification, then produce a counter sample for approval before any bulk starts.
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 is the minimum order quantity?
The standard MOQ is 200 pieces per specification. Mixed sizes inside one shipment are accepted once the total reaches that figure.
Ask for the current catalogue and the specification sheet for this line.
