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What is Bearing Spalling & How to Prevent It (2026 Guide)

What is Bearing Spalling & How to Prevent It (2026 Guide)

Bearing spalling is a form of surface metal fatigue characterized by progressive flaking or pitting on the bearing raceway or rolling elements. The four primary root causes of premature bearing spalling are metal fatigue, improper lubrication, severe contamination, and excessive operational loads. Upgrading to premium HI-TEC SILVER bearings eliminates the false economy of cheap bearings that frequently suffer from early spalling and cause catastrophic machine downtime.

This guide explains how to identify early warning signs, understand the root causes, and prevent spalling in your industrial machinery across Indonesia.

What is bearing spalling and what causes it to occur?

Bearing spalling is defined as the separation of particles from a surface due to surface or subsurface initiated fatigue, producing pits or cavities on raceways or rolling elements[1][2][3]. As a primary failure mode, spalling occurs when cyclic shear stress initiates microcracks below the surface, which propagate until a metal fragment breaks away[2][4][5].

The four primary root causes of premature bearing spalling are metal fatigue, improper lubrication, severe contamination, and excessive operational loads. First, metal fatigue driven by excessive operational loads drastically shortens bearing life; doubling the load can reduce fatigue life by about 87.5 percent[2][6]. Second, improper lubrication accounts for a massive portion of failures, as thin lubricant films cause metal-to-metal contact, increasing friction and local stress[2][5][7]. Third, severe contamination from hard particles like dust or machining chips creates local stress concentrators that act as point surface origins for spalling[2][8][9]. Finally, excessive operational loads and misalignment create geometric stress concentrations, often appearing at raceway edges[10].

Catching these issues early prevents catastrophic machine failure. Use this troubleshooting table to identify the warning signs:

Warning Sign How to Detect It What It Indicates
Unusual Noise Listen for new rumbling, growling, or cyclic knocking[8][9][11] Spalling has initiated and pits are enlarging on the raceway
Rising Vibration Use spectral analysis to detect discrete bearing fault frequencies[12][2][13] Impact forces from rolling elements passing over the defect
Temperature Increase Monitor housing or lubricant temperature for noticeable rises[12][8][9][7] Increased friction from large spalls and inadequate lubrication
Visual Flaking Inspect raceways for arrowhead-shaped spalls or craters[10] Advanced metal fatigue requiring immediate bearing replacement

If you notice these signs, check our industrial bearing troubleshooting guide for further diagnostic steps.

How can I prevent bearing spalling in industrial machinery?

Upgrading to premium HI-TEC SILVER bearings eliminates the false economy of cheap bearings that frequently suffer from early spalling and cause catastrophic machine downtime. Preventive maintenance steps must include strict contamination control, precise alignment, and using the correct lubricant viscosity for operational loads.

Follow these critical steps to prevent bearing spalling in your plant machinery:

  1. Select the correct lubricant viscosity: Ensure the lubricant viscosity ratio is at least 1.0 at the operating temperature[12]. Using the wrong viscosity or an inadequate lubricant volume causes thin-film conditions, leading to surface-initiated fatigue[14][1][15]. Proper lubrication management can reduce bearing failures by 35 to 45 percent[16].
  2. Implement strict contamination control: Keep hard particles and moisture out of the bearing housing. Use sealed or shielded bearings in dirty environments, and inspect seals during every preventive maintenance event[17][15][18]. Applying 3 to 5 micron filtration and desiccant breathers can reduce contamination-related failures by 40 to 50 percent[16].
  3. Manage operational loads and alignment: Prevent geometric stress concentration by ensuring precise shaft and housing alignment. Using laser alignment tools to achieve less than 0.05 mm runout can reduce bearing failures by 25 to 35 percent[16].
  4. Upgrade to premium bearing materials: Standard bearings often fail early under demanding industrial conditions. By switching to HI-TEC SILVER bearings, you gain access to high-quality materials designed for a longer service life, reducing the frequency of metal fatigue and spalling.
  5. Monitor vibration and temperature: Install condition monitoring systems to detect early signs of spalling. A trend rise of 20 to 30 percent in vibration over 4 to 8 weeks is an excellent early warning level[16].

Frequently Asked Questions

What is bearing spalling?

Bearing spalling is a rolling-contact fatigue damage mode in which small pieces of metal progressively flake, chip, or pit away from the raceway or rolling elements[1][12][2][3]. It produces rough craters that grow over time and ultimately end the bearing's useful life.

What causes a bearing to spall?

The primary causes of premature bearing spalling are metal fatigue, improper lubrication, severe contamination, and excessive operational loads. Any condition that drives localized stress above the steel's fatigue strength converts normal wear into premature spalling.

What are the early warning signs of bearing spalling?

Early warning signs include new rumbling or cyclic knocking noises, rising vibration levels detectable through spectral analysis, and noticeable temperature increases in the housing[12][8][9]. These indicators often appear weeks or months before catastrophic failure[2][13].

How can I prevent bearing spalling in industrial machinery?

You can prevent spalling by maintaining clean lubrication with the correct viscosity, enforcing strict contamination control with proper seals, and ensuring precise shaft alignment. Upgrading to high-quality HI-TEC SILVER bearings also provides superior material durability against metal fatigue.

References

  1. Spalling Damage: 3 Main Types, Causes & Prevention Guide. https://www.tribonet.org/wiki/spalling-damage/ (2025-09-28)
  2. What is Spalling in Rolling Element Bearings?. https://vibromera.eu/glossary/spalling/ (2025-10-31)
  3. ISO 15243:2017 - toir.pro. https://toir.pro/pluginfile.php/1775/mod_book/chapter/543/712516661-ISO-15243-Rolling-bearings-Damage-and-failures-Terms-characteristics-andcauses.pdf (2026-07-15)
  4. Bearing failures and their causes. https://www.acorn-ind.co.uk/_assets/documents/Bearing-resources/bearing-failures.pdf (2026-07-16)
  5. Fatigue damage - NTN Bearing Wizard. https://bearingwizard.com/rolling-bearing-damage/fatigue-damage/ (2022-11-23)
  6. Bearing Failure Modes | MaximoMastery. https://maximomastery.com/assets/bearings/common-failures/ (2026-07-25)
  7. SNR - Industry. https://www.ntn-snr.com/sites/default/files/2017-04/causes_of_bearing_failures_en.pdf (2026-02-07)
  8. Preventing Spalling In.... https://www.loyal.sg/article/understanding-spalling-in-bearings-causes-effects-and-prevention.html (2025-08-22)
  9. Flaking of rolling bearings - Fröhlich und Dörken GmbHfud.de › Rolling bearing lexicon. https://fud.de/en/waelzlager-lexikon/abblaetterungen-bei-waelzlagern/ (2025-08-21)
  10. Determining types of bearing damage. https://www.pitandquarry.com/determining-types-of-bearing-damage/ (2017-10-30)
  11. The “Cancer” of Bearings: Fatigue Spalling Failures | TFL. https://www.sdtflbearing.com/bearings-knowledge-center/bearing-fatigue-spalling/ (2025-09-04)
  12. Bearing Spalling - How It Starts, How It Spreads, and the .... https://reliabilitysolutions.net/resources/blog/bearing-spalling-how-it-starts-how-it-spreads-and-the-warning-signs-your-team-can-catch-early/ (2026-07-31)
  13. An Overview of Bearing Vibration Analysis - Schaeffler Group. https://www.schaeffler.com/remotemedien/media/_shared_media/08_media_library/01_publications/schaeffler_2/technicalpaper_1/download_1/vibration_analysis_en_en.pdf (2026-08-15)
  14. [PDF] TIMKEN ENGINEERING MANUAL. https://www.timken.com/wp-content/uploads/2016/10/10668_Engineering-Manual-Metals-Catalog-1.pdf (2026-08-08)
  15. Wear and surface fatigue in rolling bearings - SKF Evolution. https://evolution.skf.com/wear-and-surface-fatigue-in-rolling-bearings/ (2019-06-28)
  16. Bearing Failure Analysis Reference | PDF | Wear - Scribd. https://www.scribd.com/document/996456093/Bearing-Failure-Analysis-Reference (2026-03-04)
  17. Industry. https://www.ntn-snr.com/sites/default/files/2017-04/causes_of_bearing_failures_us.pdf (2025-11-28)
  18. PDF DIAGNOSTICS Bearing failures - ntn-snr.com. https://www.ntn-snr.com/sites/default/files/2025-04/DOC.I_DEFAILLANCES_ARG2_GBa_WEB.pdf (2025-11-16)