Vehicle Speedometer Tachometer Specification Example for Emergency Vehicles: Vented Design
Vehicle Speedometer Tachometer Specification Example for Emergency Vehicles: Vented Design
This is a worked specification for vehicle speedometer tachometer in a vented design 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 vented design version exists because the duty cycle on emergency vehicles is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually reorders that did not match the approved sample.

Example specification
| Item | Vehicle Speedometer Tachometer |
|---|---|
| Application | Emergency Vehicles |
| Version | Vented Design |
| Base material | Kevlar Composite |
| Controlled dimensions | 6 key dimensions, recorded per lot |
| Tolerance band | ±0.2 mm |
| Finish | as machined |
| MOQ | 500 pieces per specification |
| Sampling | 14 working days, 5 days per revision |
| Compliance | ISO 9001 |
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
- laser cutting
- surface grinding
- rubber vulcanisation
- cold forging
- heat treatment
- assembly line testing
Where this example applies
Programmes that run vented design most often specify this build for emergency vehicles. Related applications include workshop replacements, construction equipment, long-haul trucks, three-wheelers, off-road bikes.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 2.5 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 long does sampling take?
Samples leave the factory in 14 working days, and each revision round adds about 5 days once you have seen the first piece.
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 500 pieces per line.
Send the specification you are working to and we will confirm what we can match, what we would change and why.



