Steel Wheel Hub Specification Example for Emergency Vehicles: Vented Design
Steel Wheel Hub Specification Example for Emergency Vehicles: Vented Design
This is a worked specification for steel wheel hub 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 packing that arrived crushed at the port.
Example specification
| Item | Steel Wheel Hub |
|---|---|
| Application | Emergency Vehicles |
| Version | Vented Design |
| Base material | Titanium Alloy |
| Controlled dimensions | 5 key dimensions, recorded per lot |
| Tolerance band | ±0.5 mm |
| Finish | powder coated |
| MOQ | 2,000 pieces per specification |
| Sampling | 14 working days, 3 days per revision |
| Compliance | SAE J431 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Titanium Alloy, 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
- shot blasting
- robot welding
- heat treatment
- injection moulding
- assembly line testing
- sintering
Where this example applies
Programmes that run vented design most often specify this build for emergency vehicles. Related applications include dealership service, city buses, assembly programmes, emergency vehicles, courier fleets.
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 is the minimum order quantity?
The standard MOQ is 2000 pieces per specification. Mixed sizes inside one shipment are accepted once the total reaches that figure.
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.
How long does sampling take?
Samples leave the factory in 14 working days, and each revision round adds about 3 days once you have seen the first piece.
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.
Send the part number, the annual volume and the target market, and we will come back with a specification and a sampling plan.
