Car Door Assembly Specification Example for Trailer Axles: All-Weather Version
Car Door Assembly Specification Example for Trailer Axles: All-Weather Version
This is a worked specification for car door assembly in a all-weather version 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 all-weather version version exists because the duty cycle on trailer axles is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually a fitment that looked right on paper and failed on the bench.
Example specification
| Item | Car Door Assembly |
|---|---|
| Application | Trailer Axles |
| Version | All-Weather Version |
| Base material | Zinc Plated Steel |
| Controlled dimensions | 4 key dimensions, recorded per lot |
| Tolerance band | ±0.2 mm |
| Finish | as machined |
| MOQ | 2,000 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 — Zinc Plated 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
- heat treatment
- electroplating
- CNC machining
- precision stamping
- injection moulding
- ultrasonic cleaning
Where this example applies
Programmes that run all-weather version most often specify this build for trailer axles. Related applications include courier fleets, rental motorcycles, light trucks, agricultural trailers, construction equipment.
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
How long does sampling take?
Samples leave the factory in 10 working days, and each revision round adds about 3 days once you have seen the first piece.
What testing is included?
Standard lots ship with dimensional and hardness reports. SAE J431 documentation is issued with the shipment when your market requires it.
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 2000 pieces per line.
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.
Send the specification you are working to and we will confirm what we can match, what we would change and why.
