Engine Piston Ring Set Specification Example for City Buses: Adjustable Type
Engine Piston Ring Set Specification Example for City Buses: Adjustable Type
This is a worked specification for engine piston ring set in a adjustable 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 adjustable 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 premature wear on the first batch.
Example specification
| Item | Engine Piston Ring Set |
|---|---|
| Application | City Buses |
| Version | Adjustable Type |
| Base material | Kevlar Composite |
| Controlled dimensions | 4 key dimensions, recorded per lot |
| Tolerance band | ±0.2 mm |
| Finish | as machined |
| MOQ | 200 pieces per specification |
| Sampling | 14 working days, 5 days per revision |
| Compliance | ISO/TS 16949 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Kevlar 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
- heat treatment
- die casting
- ultrasonic cleaning
- surface grinding
- anodising
- sintering
Where this example applies
Programmes that run adjustable type most often specify this build for city buses. Related applications include fleet maintenance, emergency vehicles, passenger cars, export programmes, light trucks.
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 14 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. ISO/TS 16949 documentation is issued with the shipment when your market requires it.
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.
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.
