Car Door Assembly Specification Example for Agricultural Trailers: Budget Line
Car Door Assembly Specification Example for Agricultural Trailers: Budget Line
This is a worked specification for car door assembly 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 agricultural trailers 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 | Car Door Assembly |
|---|---|
| Application | Agricultural Trailers |
| Version | Budget Line |
| Base material | Carbon Fibre Composite |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.05 mm |
| Finish | painted |
| MOQ | 500 pieces per specification |
| Sampling | 7 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 Fibre Composite, 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
- robot welding
- ultrasonic cleaning
- surface grinding
- precision stamping
- anodising
- rubber vulcanisation
Where this example applies
Programmes that run budget line most often specify this build for agricultural trailers. Related applications include light trucks, long-haul trucks, municipal fleets, scooter fleets, passenger cars.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 1.5 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 is the minimum order quantity?
The standard MOQ is 500 pieces per specification. Mixed sizes inside one shipment are accepted once the total reaches that figure.
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 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.
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 500 pieces per line.
Share a sample or a drawing and we will quote against a written specification, not against a photograph.



