Steel Piston Pin Specification Example for City Buses: Lightweight Version
Steel Piston Pin Specification Example for City Buses: Lightweight Version
This is a worked specification for steel piston pin in a lightweight version 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 lightweight version 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 | Steel Piston Pin |
|---|---|
| Application | City Buses |
| Version | Lightweight Version |
| Base material | Chromed Steel |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.05 mm |
| Finish | zinc plated |
| 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 — Chromed 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
- robot welding
- heat treatment
- ultrasonic cleaning
- surface grinding
- sintering
- precision stamping
Where this example applies
Programmes that run lightweight version most often specify this build for city buses. Related applications include rental motorcycles, emergency vehicles, fleet maintenance, courier fleets, 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
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 200 pieces per line.
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.
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.
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.
Ask for the current catalogue and the specification sheet for this line.



