Semi Truck Axle Specification Example for Trailer Axles: Fixed Type
Semi Truck Axle Specification Example for Trailer Axles: Fixed Type
This is a worked specification for semi truck axle in a fixed type 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 fixed type 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 warranty claims traced back to a single lot.
Example specification
| Item | Semi Truck Axle |
|---|---|
| Application | Trailer Axles |
| Version | Fixed Type |
| Base material | Stainless Steel |
| Controlled dimensions | 4 key dimensions, recorded per lot |
| Tolerance band | ±0.2 mm |
| Finish | as machined |
| MOQ | 2,000 pieces per specification |
| Sampling | 7 working days, 5 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 — Stainless 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
- powder coating
- die casting
- CNC machining
- shot blasting
- anodising
Where this example applies
Programmes that run fixed type most often specify this build for trailer axles. Related applications include aftermarket retail, emergency vehicles, fleet maintenance, camper conversions, dealership service.
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
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.
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.
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.
Send the specification you are working to and we will confirm what we can match, what we would change and why.
