Ceramic Shafts, Sleeves & Bushings
Diamond-ground alumina shafts, sleeves and bushings held to ±0.005 mm for pumps, valves, flow meters and metering equipment.
Where a metal shaft corrodes, wears oval or contaminates the medium, an alumina replacement frequently outlasts it several times over — provided the tolerance and the surface finish are right, which is what the diamond grinding is for.
Where it is used
- Slurry pump shafts and shaft sleeves
- Valve plugs, seats and trim for abrasive or corrosive service
- Flow meter and metering pump components
- Rotary and linear guide bushings in clean or corrosive environments
- Spacers, wear rings and locating pins in processing equipment
Tolerances
| Feature | Achievable |
|---|---|
| Outside diameter, ground | ± 0.005 mm |
| Bore diameter, ground | ± 0.010 mm (below Ø3 mm wider) |
| Length, ground | ± 0.02 mm |
| Concentricity | 0.01 mm |
| Roundness | 0.005 mm |
| Surface finish | Ra 0.1 µm lapped |
| Straightness | 0.01 mm / 100 mm |
Long parts with a high length-to-diameter ratio are harder to hold; send the drawing and we will confirm what is feasible rather than assume it.
Material choice
- General wear and corrosion resistance → AL-95
- Fine tolerances, sealing faces, chemical duty → AL-99
- Vacuum, semiconductor, medical or high-purity → AL-99.7
- Repeated light impact at the edges → ZTA
Design notes for ceramic shafts
- Avoid press fits that load the ceramic in tension — use a shrink ring or an adhesive bond instead.
- Radius every shoulder. A square shoulder is a crack starter in a fired part.
- Where the shaft has to transmit torque, use a keyway or a flat ground before firing rather than after.
- Sealing against ceramic requires a specified surface finish; tell us the seal type and we will grind to suit.
Send the drawing for a feasibility check
We will confirm the tolerance we can hold, the grade we recommend and the price — usually the same working day.
Send us your drawing — get a quotation with a firm lead time
PDF, DWG, STEP, IGES or a photo with the critical dimensions marked. Engineering review within one working day.