The cage separates and guides rolling elements; it is not a replacement for the raceways' load-carrying function. A damaged cage can be an outcome of another problem, so retain fragments and inspect the entire bearing before assigning a cause.
Use the illustration to locate the kind of feature being discussed, not to certify the condition of a real part.
Inspect pocket bridges, side faces and guiding surfaces for fracture, distortion or wear.
Retain fragments and their positions. Check handling, mounting, load, vibration, speed changes, lubrication and temperature history.
A broken cage need not be the initiating failure. Changing cage material or fitting an arbitrary cage from another bearing is not a verified remedy.
Technical basis: NSK Bearing Doctor, individual damage-type references. Original BearingScope illustrations and investigation prompts, reviewed 4 October 2026. Colour, shape and depth are illustrative; source snapshots are retained in the internal audit.
A broken cage is an observation, not proof that its material was unsuitable. NSK lists handling or mounting problems, abnormal loading, vibration, speed changes, lubrication and temperature among possible contributors. More than one may be present.
On smaller screens, scroll the table sideways to read all columns.
| Observed evidence | Questions to investigate | Do not conclude from this alone |
|---|---|---|
| Broken pocket bridge or pillar | Did damage begin during handling, assembly or operation? Are fragments and neighbouring rolling surfaces marked? | That changing to a metal cage will prevent recurrence. |
| Pocket or guide-surface wear | Are the lubrication record, alignment and operating history consistent with the design? | A definite cause from a single photograph. |
| Deformed cage side or uneven marks | What assembly loads, shocks, vibration or misalignment occurred? | An allowable wear limit without the manufacturer's criterion. |
| Temperature event or speed transient | Retain temperature measurements, lubricant details and acceleration/deceleration history. | A replacement speed rating copied from another cage variant. |
Isolate the machine using its safe shutdown procedure. Preserve loose pieces and their locations, photograph both faces, and label the complete bearing and machine position. Keep observed damage separate from suspected causes in the inspection record.
Check the original marking, cage material and guidance against the product record. Record mounting practice, loading, speed history and lubrication before proposing a change. If another cage variant is considered, recheck the entire bearing specification; nominal dimensions alone do not approve it.
Do not straighten a cracked cage, mix loose parts from different bearings or operate without a cage unless the original design specifically permits that construction. Reuse or repair requires a documented procedure for the exact bearing.
Reviewed 3 October 2026. Technical basis: NSK Bearing Doctor, Cage Damage; SKF cage construction and material guidance. This is an investigation aid, not an automatic diagnosis or repair approval.
| Observation or context | Interpretation to consider | Verification needed |
|---|---|---|
| Cracks or broken cage pieces | Loss of guiding function | Record fragment positions and secondary contact damage. |
| Polished or worn pockets | Contact conditions changed | Inspect alignment, lubrication, loading and element motion. |
| A different cage suffix on a replacement | Material or design changed | Verify the exact manufacturer's suffix, speed and temperature limits. |
Stop operation and prevent fragments from circulating through the assembly. Preserve recovered material for inspection.
Read the complete original designation rather than choosing another bearing solely by d×D×B.
Record acceleration, shock, vibration and lubrication history. Separate observed facts from a proposed failure mechanism.
Check the cage material and guidance arrangement in the exact model documentation. Do not rank brass, steel and polymer cages with a universal best-to-worst list.
Keep this checklist with your inspection or comparison. Checking a box only records that you have collected the item; it does not certify the bearing.
0 of 4 information groups recorded.
Original BearingScope workflow, written for catalogue research and comparison. Manufacturer material is used to check principles, not copied as a product endorsement or substituted for model-specific instructions. Reviewed 1 October 2026.
Source addresses and collection status are retained in the internal audit. No unpublished dimensions, torque settings, service intervals or interchange approvals are inferred.