Mechanical Coupling Specification Example for City Buses: Standard Replacement
Mechanical Coupling Specification Example for City Buses: Standard Replacement
This is a worked specification for mechanical coupling in a standard replacement 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 standard replacement 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 packing that arrived crushed at the port.
Example specification
| Item | Mechanical Coupling |
|---|---|
| Application | City Buses |
| Version | Standard Replacement |
| Base material | Magnesium Alloy |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.2 mm |
| Finish | as machined |
| MOQ | 2,000 pieces per specification |
| Sampling | 10 working days, 5 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 — Magnesium 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
- anodising
- electroplating
- cold forging
- assembly line testing
- powder coating
- ultrasonic cleaning
Where this example applies
Programmes that run standard replacement most often specify this build for city buses. Related applications include long-haul trucks, dealership service, boat trailers, off-road bikes, utility trailers.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 2.5 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
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.
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.
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.
What testing is included?
Standard lots ship with dimensional and hardness reports. REACH documentation is issued with the shipment when your market requires it.
Send the part number, the annual volume and the target market, and we will come back with a specification and a sampling plan.
