In a cleanroom or a washdown cell the bearing is a contamination source, and stainless removes half of that contamination. Robotics & Automation duty is high cycle count, oscillating motion and zero tolerance for play; the material is what decides whether the bearing survives it.
| Industry duty | very high duty cycle, small oscillating displacements and stiffness demands |
|---|---|
| Typical media | clean air, occasional grease starvation at reversal points |
| Housing temperature | 0 to +60 °C |
| Material and grade | 440C martensitic stainless steel |
| Hardness | 58–60 HRC |
| Temperature ceiling | 250 °C |
| Corrosion / chemical | fresh water, food and mild chemicals; pits in chlorides |
| Relative cost | ≈3× of a standard 52100 bearing |
A cleanroom counts particles, and a bearing sheds them from three places: rust, grease and cage wear. Stainless removes the first, which is the one that appears in a washdown cell after every cleaning cycle. The grease and the cage still have to be chosen for the application, which is why the material choice and the lubrication choice are separate decisions.
| Position | Bearing type | Material / finish | Why it works there |
|---|---|---|---|
| Cleanroom linear axis | Linear guideway | 440C rail and block, dry-film lubrication | No grease migration onto the product. |
| Washdown robot wrist | Deep groove ball | 440C, 2RS, H1 grease | Survives the wash cycle between shifts. |
| Pharma vial handling | 440C bush | 440C bush, dry film | Stainless surface with no lubricant to migrate. |
| Material | Fit here | Choose it when |
|---|---|---|
| 440C | Best fit | Washdown cells and humid cleanrooms where rust is the visible defect. |
| Si3N4 | Workable alternative | Where grease must be eliminated entirely — hybrid with a PEEK cage. |
| 100Cr6 / 52100 | Workable alternative | Sealed cell with no washdown; a coated ring is enough. |
Not on its own. The grease and the cage are the particle sources in a cleanroom; stainless only removes the rust.
440C for load, 316 for chlorine. Most washdown cells use 440C and a sanitiser without free chlorine.
At low load and speed, with a dry-film or a PTFE-lined bearing. A dry stainless ball bearing will wear quickly.
Hardness, temperature, corrosion and equivalents for 440C stainless.
Read →Typical duty, recommended types and suffixes for robotics.
Read →Joints & reducers — robot joint reducers, harmonic drive supports and linear axis carriages.
Read →High cycle, no grease — high-cycle joints and vacuum or cleanroom axes where grease life limits the design.
Read →Send the position, bore size, quantity and the medium it sees. We reply with the material certificate, clearance class, lubricant and price within 30 minutes on working days.