A failed bearing carries a record of what happened to it. Reading the damage pattern before ordering a replacement is what stops the same failure repeating.
Fatigue Spalling
Flaking of the raceway surface after a long period of normal running. If it appears in the loaded zone and the bearing has run its expected hours, this is normal end of life. If it appears early, the load was higher than assumed or the lubricant film was too thin.
Brinelling And False Brinelling
True brinelling shows evenly spaced dents at rolling element pitch and comes from impact during mounting or a shock load while stationary. False brinelling shows shallow polished or rust coloured marks at the same pitch and comes from vibration while stationary, typically during transport or a long idle period.
Smearing
Material transferred between roller and raceway, caused by rolling elements skidding rather than rolling. It happens where the bearing is too lightly loaded for its speed, which is a common finding on unloaded thrust bearings and on cylindrical roller bearings in the unloaded zone.
Electrical Fluting
Regular washboard marks across the raceway, with a characteristic frosted appearance under magnification. Caused by current passing through the bearing, most often in inverter driven motors. The fix is an insulated bearing or a shaft grounding ring, not a better bearing.
Corrosion And Contamination
Rust pitting shows water ingress or condensation during storage. Dull, dented raceways with embedded particles show a failed seal or contaminated lubricant. Both point at the sealing system rather than the bearing.
Edge Loading
Damage concentrated at one end of the roller path indicates misalignment or a deflecting shaft. Replacing the bearing without correcting the alignment simply repeats the failure.
