Engine Cylinder Gasket Specification Example for Courier Fleets: Sealed Unit
Engine Cylinder Gasket Specification Example for Courier Fleets: Sealed Unit
This is a worked specification for engine cylinder gasket 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 courier fleets 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 | Engine Cylinder Gasket |
|---|---|
| Application | Courier Fleets |
| Version | Sealed Unit |
| Base material | High Density Foam |
| Controlled dimensions | 4 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 | CCC |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — High Density Foam, 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
- sintering
- laser cutting
- electroplating
- rubber vulcanisation
- assembly line testing
- precision stamping
Where this example applies
Programmes that run sealed unit most often specify this build for courier fleets. Related applications include camper conversions, municipal fleets, boat trailers, aftermarket retail, workshop replacements.
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
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.
What is the minimum order quantity?
The standard MOQ is 3000 pieces per specification. Mixed sizes inside one shipment are accepted once the total reaches that figure.
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.
Share a sample or a drawing and we will quote against a written specification, not against a photograph.



