Engine Assembly Specification Example for Construction Equipment: Sealed Unit
Engine Assembly Specification Example for Construction Equipment: Sealed Unit
This is a worked specification for engine assembly in a sealed unit 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 sealed unit version exists because the duty cycle on construction equipment 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 | Engine Assembly |
|---|---|
| Application | Construction Equipment |
| Version | Sealed Unit |
| Base material | Kevlar Composite |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.2 mm |
| Finish | zinc plated |
| MOQ | 200 pieces per specification |
| Sampling | 7 working days, 3 days per revision |
| Compliance | SGS |
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
- injection moulding
- precision stamping
- shot blasting
- powder coating
- CNC machining
- die casting
Where this example applies
Programmes that run sealed unit most often specify this build for construction equipment. Related applications include passenger cars, workshop replacements, camper conversions, racing teams, scooter 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.
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 200 pieces per line.
What is the minimum order quantity?
The standard MOQ is 200 pieces per specification. Mixed sizes inside one shipment are accepted once the total reaches that figure.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the SGS-compliant build instead of a fresh interpretation.
Tell us the model, the fitment and the quantity and we will hold a production slot for you.



