Engine Piston Ring Set Specification Example for City Buses: OEM Replacement
Engine Piston Ring Set Specification Example for City Buses: OEM Replacement
This is a worked specification for engine piston ring set in a oem 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 oem 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 inconsistent hardness between lots.
Example specification
| Item | Engine Piston Ring Set |
|---|---|
| Application | City Buses |
| Version | OEM Replacement |
| Base material | ABS Plastic |
| Controlled dimensions | 4 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | powder coated |
| MOQ | 2,000 pieces per specification |
| Sampling | 7 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 — ABS Plastic, 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
- cold forging
- shot blasting
- injection moulding
- CNC machining
- robot welding
- powder coating
Where this example applies
Programmes that run oem replacement most often specify this build for city buses. Related applications include camper conversions, passenger cars, assembly programmes, dealership service, rental motorcycles.
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 7 working days, and each revision round adds about 5 days once you have seen the first piece.
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.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the ISO/TS 16949-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.
Send the specification you are working to and we will confirm what we can match, what we would change and why.
