Diesel Engine Parts Specification Example for Trailer Axles: Heavy Duty
Diesel Engine Parts Specification Example for Trailer Axles: Heavy Duty
This is a worked specification for diesel engine parts 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 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 | Diesel Engine Parts |
|---|---|
| Application | Trailer Axles |
| Version | Heavy Duty |
| Base material | PU Leather |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.5 mm |
| Finish | painted |
| MOQ | 1,000 pieces per specification |
| Sampling | 10 working days, 5 days per revision |
| Compliance | ECE R90 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — PU Leather, 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
- gravity casting
- laser cutting
- die casting
- robot welding
- electroplating
- sintering
Where this example applies
Programmes that run heavy duty most often specify this build for trailer axles. Related applications include emergency vehicles, courier fleets, utility trailers, light trucks, assembly programmes.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 4.0 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
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 1000 pieces per line.
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.
What testing is included?
Standard lots ship with dimensional and hardness reports. ECE R90 documentation is issued with the shipment when your market requires it.
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.
Send the specification you are working to and we will confirm what we can match, what we would change and why.



