High Efficiency DC Converter Specification Example for Long-Haul Trucks: Folding Type
High Efficiency DC Converter Specification Example for Long-Haul Trucks: Folding Type
This is a worked specification for high efficiency dc converter 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 long-haul trucks 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 | High Efficiency DC Converter |
|---|---|
| Application | Long-Haul Trucks |
| Version | Folding Type |
| Base material | EPDM Rubber |
| Controlled dimensions | 4 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | anodised |
| MOQ | 1,000 pieces per specification |
| Sampling | 7 working days, 5 days per revision |
| Compliance | DOT |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — EPDM Rubber, 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
- injection moulding
- rubber vulcanisation
- powder coating
- laser cutting
- cold forging
- heat treatment
Where this example applies
Programmes that run folding type most often specify this build for long-haul trucks. Related applications include delivery vans, agricultural trailers, aftermarket retail, workshop replacements, courier fleets.
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
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 DOT-compliant build instead of a fresh interpretation.
What testing is included?
Standard lots ship with dimensional and hardness reports. DOT documentation is issued with the shipment when your market requires it.
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 1000 pieces per line.
Ask for the current catalogue and the specification sheet for this line.



