Mining is where chrome steel is pushed hardest: shock, abrasion and water, with maintenance access measured in hours rather than days. Mining & Aggregate duty is shock, abrasion and water sprays with little maintenance access; the material is what decides whether the bearing survives it.
| Industry duty | shock load from crusher jaws and falling ore, in continuous abrasive dust |
|---|---|
| Typical media | ore dust, slurry, water spray |
| Housing temperature | −20 to +120 °C |
| Material and grade | through-hardened chrome steel — 100Cr6 / 52100 |
| Hardness | 59–65 HRC |
| Temperature ceiling | 120 °C (200 °C stabilised) |
| Corrosion / chemical | none — rusts without protection |
| Relative cost | 1.0× of a standard 52100 bearing |
A jaw crusher does not apply a steady load, it applies a block of rock. The rating life calculation assumes a load spectrum, and a single blocked cavity can brinell a raceway in one pass. That is why mining practice is to oversize, to use a spherical seat that tolerates frame deflection, and to accept that the bearing is a wear part in a plant where the structure is never perfectly stiff.
| Position | Bearing type | Material / finish | Why it works there |
|---|---|---|---|
| Jaw crusher pitman | Self-aligning roller | 52100, 222xx/223xx, C3/C4, sealed | Shock plus misalignment; the spherical seat absorbs frame deflection. |
| Vibrating screen | Self-aligning roller | 52100, C4, special clearance | High cycle at 900–1,200 rpm with an eccentric load. |
| Conveyor head pulley | Ball bearing unit | 52100 insert, heavy-duty seal | Dust and water spray; the seal decides the life. |
| Apron feeder roller | Tapered roller | 52100, matched pair | Combined load at low speed. |
| Material | Fit here | Choose it when |
|---|---|---|
| 100Cr6 / 52100 | Best fit | Standard plant practice: oversize the bearing, upgrade the seal. |
| Bronze | Workable alternative | Very slow, high-load shafts where conformability beats fatigue life. |
| 440C | Workable alternative | Wash plant and slurry positions where rust is the failure mode. |
Because the rating assumes a load spectrum. A blocked cavity, a tramp metal event or a foundation that has settled applies loads the calculation never saw.
To a point. A larger bearing has a thicker section and more thermal mass, but it also needs more grease and a stiffer housing. The housing usually decides.
Only with a labyrinth plus a grease purge. A single lip seal will not hold dust at those speeds and vibration levels.
Hardness, temperature, corrosion and equivalents for 52100 chrome steel.
Read →Typical duty, recommended types and suffixes for mining & aggregate.
Read →Crusher bushes — cone crusher eccentric bushes, pitman seats and slow shaft bearings.
Read →Wash plant & slurry — wash plant, dewatering and slurry pump positions where water is constant.
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.