Tandem Trailer Axles Specification Example for City Buses: Premium Line
Tandem Trailer Axles Specification Example for City Buses: Premium Line
This is a worked specification for tandem trailer axles in a premium 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 premium line version exists because the duty cycle on city buses is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually lead time that slipped twice before bulk started.
Example specification
| Item | Tandem Trailer Axles |
|---|---|
| Application | City Buses |
| Version | Premium Line |
| Base material | Reinforced Nylon |
| Controlled dimensions | 6 key dimensions, recorded per lot |
| Tolerance band | ±0.5 mm |
| Finish | zinc plated |
| MOQ | 500 pieces per specification |
| Sampling | 10 working days, 5 days per revision |
| Compliance | DOT |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Reinforced Nylon, 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
- die casting
- robot welding
- cold forging
- powder coating
- injection moulding
- laser cutting
Where this example applies
Programmes that run premium line most often specify this build for city buses. Related applications include three-wheelers, long-haul trucks, off-road bikes, camper conversions, export 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
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.
What testing is included?
Standard lots ship with dimensional and hardness reports. DOT documentation is issued with the shipment when your market requires it.
How long does sampling take?
Samples leave the factory in 10 working days, and each revision round adds about 5 days once you have seen the first piece.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the DOT-compliant build instead of a fresh interpretation.
Send the part number, the annual volume and the target market, and we will come back with a specification and a sampling plan.
