Automotive Head Seal Specification Example for Light Trucks: OEM Replacement
Automotive Head Seal Specification Example for Light Trucks: OEM Replacement
This is a worked specification for automotive head seal 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 light trucks is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually a specification nobody had written down.
Example specification
| Item | Automotive Head Seal |
|---|---|
| Application | Light Trucks |
| Version | OEM Replacement |
| Base material | Semi-Metallic Compound |
| Controlled dimensions | 6 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | powder coated |
| MOQ | 200 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 — Semi-Metallic Compound, 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
- rubber vulcanisation
- cold forging
- precision stamping
- assembly line testing
- die casting
- electroplating
Where this example applies
Programmes that run oem replacement most often specify this build for light trucks. Related applications include passenger cars, racing teams, courier fleets, construction equipment, boat trailers.
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 10 working days, and each revision round adds about 3 days once you have seen the first piece.
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 200 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.
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.
Send the specification you are working to and we will confirm what we can match, what we would change and why.
