Exhaust System Resonator Specification Example for Workshop Replacements: Sealed Unit
Exhaust System Resonator Specification Example for Workshop Replacements: Sealed Unit
This is a worked specification for exhaust system resonator in a sealed unit 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 sealed unit version exists because the duty cycle on workshop replacements is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually warranty claims traced back to a single lot.

Example specification
| Item | Exhaust System Resonator |
|---|---|
| Application | Workshop Replacements |
| Version | Sealed Unit |
| Base material | Reinforced Nylon |
| Controlled dimensions | 5 key dimensions, recorded per lot |
| Tolerance band | ±0.05 mm |
| Finish | as machined |
| MOQ | 500 pieces per specification |
| Sampling | 10 working days, 5 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 — Reinforced Nylon, 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.
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Processes involved
- injection moulding
- ultrasonic cleaning
- powder coating
- die casting
- cold forging
- heat treatment
Where this example applies
Programmes that run sealed unit most often specify this build for workshop replacements. Related applications include city buses, dealership service, assembly programmes, camper conversions, fleet maintenance.
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
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.
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 500 pieces per line.
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.
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.
Send the specification you are working to and we will confirm what we can match, what we would change and why.



