Automotive Head Seal Specification Example for City Buses: Folding Type
Automotive Head Seal Specification Example for City Buses: Folding Type
This is a worked specification for automotive head seal in a folding type 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 folding type 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 supplier who changed material without saying so.
Example specification
| Item | Automotive Head Seal |
|---|---|
| Application | City Buses |
| Version | Folding Type |
| Base material | Chromed Steel |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | painted |
| MOQ | 2,000 pieces per specification |
| Sampling | 14 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 — Chromed 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
- powder coating
- heat treatment
- electroplating
- ultrasonic cleaning
- surface grinding
- rubber vulcanisation
Where this example applies
Programmes that run folding type most often specify this build for city buses. Related applications include city buses, trailer axles, utility trailers, boat trailers, agricultural 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 14 working days, and each revision round adds about 3 days once you have seen the first piece.
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 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 testing is included?
Standard lots ship with dimensional and hardness reports. CCC documentation is issued with the shipment when your market requires it.
Share a sample or a drawing and we will quote against a written specification, not against a photograph.
