Automotive Head Seal Specification Example for Utility Trailers: Heavy Duty
Automotive Head Seal Specification Example for Utility Trailers: Heavy Duty
This is a worked specification for automotive head seal in a heavy duty 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 heavy duty version exists because the duty cycle on utility trailers is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually lead time that slipped twice before bulk started.
Example specification
| Item | Automotive Head Seal |
|---|---|
| Application | Utility Trailers |
| Version | Heavy Duty |
| Base material | Kevlar Composite |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | powder coated |
| MOQ | 3,000 pieces per specification |
| Sampling | 7 working days, 5 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 — Kevlar Composite, 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
- die casting
- CNC machining
- heat treatment
- cold forging
- anodising
- electroplating
Where this example applies
Programmes that run heavy duty most often specify this build for utility trailers. Related applications include long-haul trucks, light trucks, delivery vans, scooter fleets, emergency vehicles.
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
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.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the SAE J431-compliant build instead of a fresh interpretation.
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.
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.
Ask for the current catalogue and the specification sheet for this line.
