Semi Truck Axle Specification Example for Assembly Programmes: Sealed Unit
Semi Truck Axle Specification Example for Assembly Programmes: Sealed Unit
This is a worked specification for semi truck axle in a sealed unit 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 sealed unit version exists because the duty cycle on assembly programmes is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually inconsistent hardness between lots.

Example specification
| Item | Semi Truck Axle |
|---|---|
| Application | Assembly Programmes |
| Version | Sealed Unit |
| Base material | Aluminium Alloy |
| Controlled dimensions | 5 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | anodised |
| MOQ | 200 pieces per specification |
| Sampling | 7 working days, 3 days per revision |
| Compliance | ISO 9001 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Aluminium Alloy, 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
- sintering
- powder coating
- anodising
- shot blasting
- laser cutting
- robot welding
Where this example applies
Programmes that run sealed unit most often specify this build for assembly programmes. Related applications include delivery vans, camper conversions, three-wheelers, city buses, construction equipment.
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
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.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the ISO 9001-compliant build instead of a fresh interpretation.
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.
Share a sample or a drawing and we will quote against a written specification, not against a photograph.



