Engine Piston Ring Set Specification Example for City Buses: Waterproof Version
Engine Piston Ring Set Specification Example for City Buses: Waterproof Version
This is a worked specification for engine piston ring set in a waterproof 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 waterproof 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 inconsistent hardness between lots.
Example specification
| Item | Engine Piston Ring Set |
|---|---|
| Application | City Buses |
| Version | Waterproof Version |
| Base material | Ceramic Composite |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | as machined |
| MOQ | 3,000 pieces per specification |
| Sampling | 10 working days, 3 days per revision |
| Compliance | RoHS |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Ceramic Composite, 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
- assembly line testing
- precision stamping
- laser cutting
- powder coating
- anodising
- shot blasting
Where this example applies
Programmes that run waterproof version most often specify this build for city buses. Related applications include off-road bikes, assembly programmes, trailer axles, passenger cars, export programmes.
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 long does sampling take?
Samples leave the factory in 10 working days, and each revision round adds about 3 days once you have seen the first piece.
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.
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. RoHS documentation is issued with the shipment when your market requires it.
Tell us the model, the fitment and the quantity and we will hold a production slot for you.
