Hydraulic Piston Specification Example for Three-Wheelers: Sealed Unit
Hydraulic Piston Specification Example for Three-Wheelers: Sealed Unit
This is a worked specification for hydraulic piston 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 three-wheelers is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually warranty claims traced back to a single lot.
Example specification
| Item | Hydraulic Piston |
|---|---|
| Application | Three-Wheelers |
| Version | Sealed Unit |
| Base material | Brass |
| Controlled dimensions | 3 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | anodised |
| MOQ | 1,000 pieces per specification |
| Sampling | 10 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 — Brass, 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
- ultrasonic cleaning
- powder coating
- electroplating
- die casting
- robot welding
- precision stamping
Where this example applies
Programmes that run sealed unit most often specify this build for three-wheelers. Related applications include municipal fleets, city buses, off-road bikes, trailer axles, emergency vehicles.
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
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.
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.
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 1000 pieces per line.
How long does sampling take?
Samples leave the factory in 10 working days, and each revision round adds about 3 days once you have seen the first piece.
Share a sample or a drawing and we will quote against a written specification, not against a photograph.
