Engine Assembly Specification Example for City Buses: Fixed Type
Engine Assembly Specification Example for City Buses: Fixed Type
This is a worked specification for engine assembly 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 city buses 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 | Engine Assembly |
|---|---|
| Application | City Buses |
| Version | Fixed Type |
| Base material | PVC Coated Fabric |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.05 mm |
| Finish | zinc plated |
| MOQ | 3,000 pieces per specification |
| Sampling | 7 working days, 3 days per revision |
| Compliance | REACH |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — PVC Coated Fabric, 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
- surface grinding
- laser cutting
- gravity casting
- die casting
- ultrasonic cleaning
- injection moulding
Where this example applies
Programmes that run fixed type most often specify this build for city buses. Related applications include assembly programmes, workshop replacements, fleet maintenance, export programmes, scooter fleets.
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
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the REACH-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.
What testing is included?
Standard lots ship with dimensional and hardness reports. REACH documentation is issued with the shipment when your market requires it.
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.
Send the specification you are working to and we will confirm what we can match, what we would change and why.



