Automotive Head Seal Specification Example for Dealership Service: Sealed Unit
Automotive Head Seal Specification Example for Dealership Service: Sealed Unit
This is a worked specification for automotive head seal 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 dealership service is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually a supplier who changed material without saying so.
Example specification
| Item | Automotive Head Seal |
|---|---|
| Application | Dealership Service |
| Version | Sealed Unit |
| Base material | Carbon Steel |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.05 mm |
| Finish | anodised |
| MOQ | 1,000 pieces per specification |
| Sampling | 10 working days, 3 days per revision |
| Compliance | SAE J431 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Carbon Steel, 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
- precision stamping
- rubber vulcanisation
- electroplating
- robot welding
- CNC machining
Where this example applies
Programmes that run sealed unit most often specify this build for dealership service. Related applications include light trucks, dealership service, aftermarket retail, courier fleets, boat trailers.
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.
What is the minimum order quantity?
The standard MOQ is 1000 pieces per specification. Mixed sizes inside one shipment are accepted once the total reaches that figure.
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.
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.
