Automotive Head Seal Specification Example for City Buses: All-Weather Version
Automotive Head Seal Specification Example for City Buses: All-Weather Version
This is a worked specification for automotive head seal in a all-weather version 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 all-weather version version exists because the duty cycle on city buses 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 | City Buses |
| Version | All-Weather Version |
| Base material | Powder Coated Steel |
| Controlled dimensions | 4 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | anodised |
| MOQ | 500 pieces per specification |
| Sampling | 10 working days, 5 days per revision |
| Compliance | RoHS |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Powder Coated 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
- robot welding
- sintering
- CNC machining
- cold forging
- gravity casting
- shot blasting
Where this example applies
Programmes that run all-weather version most often specify this build for city buses. Related applications include trailer axles, export programmes, passenger cars, camper conversions, three-wheelers.
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.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the RoHS-compliant build instead of a fresh interpretation.
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 500 pieces per line.
What testing is included?
Standard lots ship with dimensional and hardness reports. RoHS documentation is issued with the shipment when your market requires it.
Send the specification you are working to and we will confirm what we can match, what we would change and why.



