Ball Auto Bearing Specification Example for City Buses: Drilled and Slotted
Ball Auto Bearing Specification Example for City Buses: Drilled and Slotted
This is a worked specification for ball auto bearing in a drilled and slotted 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 drilled and slotted version exists because the duty cycle on city buses is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually documentation that arrived after the container shipped.

Example specification
| Item | Ball Auto Bearing |
|---|---|
| Application | City Buses |
| Version | Drilled and Slotted |
| Base material | Powder Coated Steel |
| Controlled dimensions | 4 key dimensions, recorded per lot |
| Tolerance band | ±0.1 mm |
| Finish | powder coated |
| MOQ | 500 pieces per specification |
| Sampling | 7 working days, 3 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 — Powder Coated Steel, 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
- die casting
- heat treatment
- electroplating
- injection moulding
- assembly line testing
- sintering
Where this example applies
Programmes that run drilled and slotted most often specify this build for city buses. Related applications include export programmes, three-wheelers, city buses, construction equipment, utility trailers.
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
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.
What testing is included?
Standard lots ship with dimensional and hardness reports. ISO 9001 documentation is issued with the shipment when your market requires it.
Can you match an existing sample?
Send a sample and we will reverse-engineer the specification, then produce a counter sample for approval before any bulk starts.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the ISO 9001-compliant build instead of a fresh interpretation.
Share a sample or a drawing and we will quote against a written specification, not against a photograph.



