In a mill, bronze is the wear part: it is designed to be replaced, and it is replaced without re-machining the housing. Steel & Metallurgy duty is very high load, heat and cooling water washing the grease out; the material is what decides whether the bearing survives it.
| Industry duty | rolling force with heavy axial component, 60–200 °C at the roll neck |
|---|---|
| Typical media | mill scale, cooling water, grease |
| Housing temperature | 60 to +200 °C |
| Material and grade | cast bronze (CuSn6 / C93200) |
| Hardness | 60–80 HB |
| Temperature ceiling | 250 °C |
| Corrosion / chemical | water and seawater; needs grease or graphite plugs |
| Relative cost | ≈1.5× of a standard 52100 bearing |
A rolling bearing needs clean lubricant and a stiff seat; a mill auxiliary has neither. Scale gets into everything, the frames distort with heat, and the shaft is often already worn. Bronze works because it embeds the scale instead of spalling on it, conforms to the worn shaft, and gives warning by wearing rather than failing suddenly.
| Position | Bearing type | Material / finish | Why it works there |
|---|---|---|---|
| Guide roll bush | CuSn6 bush | Bronze bush, grease | Scale and misalignment; bronze conforms instead of spalling. |
| Table roller end | Bronze bush | Bronze bush, water-cooled seat | Low speed, high temperature, dirty. |
| Shear blade guide | Bronze wear plate | Bronze wear plate | Sliding under shock; replaceable. |
| Material | Fit here | Choose it when |
|---|---|---|
| Bronze | Best fit | Slow auxiliary shafts where wear is planned and access is short. |
| 100Cr6 / 52100 | Workable alternative | Where speed makes rolling contact worth the sealing effort. |
| POM | Workable alternative | Cool, clean auxiliary positions where lubrication is impossible. |
Because scale destroys the seal within weeks and the housing distorts with heat. A bronze bush is cheaper to replace and gives warning.
Loss of grease at temperature, usually because the grease carbonised. High-temperature grease and a shorter interval prevent it.
Yes, on run-out tables water is often the only lubricant available, and bronze handles it better than steel.
Hardness, temperature, corrosion and equivalents for cast bronze.
Read →Typical duty, recommended types and suffixes for steel mills.
Read →Roll neck & mill drives — roll neck, mill drive and run-out table positions.
Read →Hot roll necks — hot strip mill and furnace-adjacent positions above 200 °C.
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.