Cylinder Head Repair Specification Example for Courier Fleets: Heavy Duty
Cylinder Head Repair Specification Example for Courier Fleets: Heavy Duty
This is a worked specification for cylinder head repair 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 courier fleets is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually inconsistent hardness between lots.

Example specification
| Item | Cylinder Head Repair |
|---|---|
| Application | Courier Fleets |
| Version | Heavy Duty |
| Base material | Anodised Aluminium |
| Controlled dimensions | 6 key dimensions, recorded per lot |
| Tolerance band | ±0.5 mm |
| Finish | zinc plated |
| MOQ | 2,000 pieces per specification |
| Sampling | 10 working days, 3 days per revision |
| Compliance | IATF 16949 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Anodised Aluminium, 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
- electroplating
- die casting
- surface grinding
- rubber vulcanisation
- shot blasting
- assembly line testing
Where this example applies
Programmes that run heavy duty most often specify this build for courier fleets. Related applications include utility trailers, off-road bikes, emergency vehicles, courier fleets, export programmes.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 4.0 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
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 2000 pieces per line.
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.
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 testing is included?
Standard lots ship with dimensional and hardness reports. IATF 16949 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.



