ASTM D8128-22

Standard Guide for Monitoring Failure Mode Progression in Industrial Applications with Rolling Element Ball Type Bearings

SIGNIFICANCE AND USE
5.1 This guide is intended as a guideline for justification of oil test selection for monitoring rolling element ball type bearing conditions in industrial applications. Continuous benchmarking against similar applications is required to ensure lessons learned are continuously implemented.  
5.2 Selection of oil tests for the purpose of detecting rolling element ball type bearing failure modes requires good understanding of equipment design, operating requirements and surrounding conditions. Specifically, detailed knowledge is required on bearing design configuration, dimensional tolerances, load directions, design limitations, lubrication mechanisms, lubricant characteristics, and metallurgy of lubricated surfaces including bearing cages. Equipment criticality and accessibility as well as application of other monitoring techniques (for example, vibration, ultrasound or thermal images) are also critical information in this analysis process. In addition, detailed knowledge on the lubricating oil is paramount.  
5.3 To properly apply the FMEA methodology users must understand the changes the system may encounter during all operating modes, their impact on design functions and available monitoring techniques capable of detecting these changes. To assist this approach, Section 6 will provide extensive descriptions on the rolling element ball type bearing failure modes, their causes and effects.  
5.4 It is recognized that in most industrial applications vibration monitoring is the primary condition monitoring technique applied to detect failure modes, causes and effects in rolling element ball type bearings—while oil analysis is primarily used to monitor the lubricating oil properties. In the recent years, however, there is a trend toward using oil analysis in order to provide earlier detection of some failures of rolling element ball type bearings. This is particularly applicable to complex dynamic systems such as compressors, gearboxes and some gas turbines where o...
SCOPE
1.1 This guide approaches oil analysis from a failure standpoint and includes both the rolling element ball type bearing wear and fluid deterioration in industrial application.  
1.2 This guide pertains to improving equipment reliability, reducing maintenance costs and enhancing the condition-based maintenance program primarily for industrial machinery by applying analytical methodology to oil analysis program for the purpose of detecting specific failure modes.  
1.3 This guide reinforces requirements for appropriate assembly, operation within the original design envelope as well as the need for condition-based and time-based maintenance.  
1.4 This guide covers the principles of Failure Mode and Effect Analysis (FMEA) as described in Guide D7874 and its relationship to rolling element ball type bearing wear in industrial application and its fluid deterioration.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Apr-2022
• ICS: 75.100 - Lubricants, industrial oils and related products
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.96.04 - Guidelines for In-Services Lubricants Analysis

Relations

• Refers: ASTM D445-24 - Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• Effective Date: 01-Apr-2024
• Refers: ASTM D1500-24 - Standard Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
• Effective Date: 01-Mar-2024
• Refers: ASTM D4175-23a - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 15-Dec-2023
• Refers: ASTM D445-23 - Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• Effective Date: 01-Nov-2023
• Refers: ASTM D4175-23e1 - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Jul-2023
• Refers: ASTM D664-11a(2017) - Standard Test Method for Acid Number of Petroleum Products by Potentiometric Titration
• Effective Date: 01-May-2017
• Refers: ASTM D445-16 - Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• Effective Date: 15-Dec-2016
• Refers: ASTM D6595-16 - Standard Test Method for Determination of Wear Metals and Contaminants in Used Lubricating Oils or Used Hydraulic Fluids by Rotating Disc Electrode Atomic Emission Spectrometry
• Effective Date: 01-Jul-2016
• Refers: ASTM D445-14 - Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• Effective Date: 01-Jul-2014
• Refers: ASTM D445-14e1 - Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• Effective Date: 01-Jul-2014
• Refers: ASTM D7042-14 - Standard Test Method for Dynamic Viscosity and Density of Liquids by Stabinger Viscometer (and the Calculation of Kinematic Viscosity)
• Effective Date: 01-May-2014
• Refers: ASTM D7874-13 - Standard Guide for Applying Failure Mode and Effect Analysis (FMEA) to In-Service Lubricant Testing
• Effective Date: 01-Oct-2013
• Refers: ASTM D7483-13a - Standard Test Method for Determination of Dynamic Viscosity and Derived Kinematic Viscosity of Liquids by Oscillating Piston Viscometer
• Effective Date: 15-Jun-2013
• Refers: ASTM D7483-13 - Standard Test Method for Determination of Dynamic Viscosity and Derived Kinematic Viscosity of Liquids by Oscillating Piston Viscometer
• Effective Date: 01-Mar-2013
• Refers: ASTM D1500-12 - Standard Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
• Effective Date: 01-Dec-2012

Overview

ASTM D8128-22: Standard Guide for Monitoring Failure Mode Progression in Industrial Applications with Rolling Element Ball Type Bearings provides a comprehensive approach for using oil analysis to assess and manage the health of ball type rolling element bearings in industrial equipment. Developed by ASTM, this standard is designed to support improvement in equipment reliability, reduction in maintenance costs, and enhancement of condition-based maintenance programs through systematic monitoring of bearing wear and lubricant performance.

The guide emphasizes selecting oil tests based on a failure mode and effect analysis (FMEA), ensuring that oil analysis targets specific failure mechanisms rather than just general oil degradation. It supports continuous benchmarking against similar applications and positions oil analysis as a key technique alongside vibration, ultrasound, and thermal imaging in sophisticated predictive maintenance strategies.

Key Topics

• Oil Test Selection: Guidance on choosing oil analysis methods that can detect key failure modes and the progression of damage in ball type bearings.
• Failure Mode and Effect Analysis (FMEA): Applying FMEA for systematic identification and prioritization of potential bearing failure modes, their causes, and impacts.
• Bearing Failure Mechanisms: Coverage of diverse failure types including:
  • Subsurface fatigue
  • Surface distress
  • Abrasive and adhesive wear
  • Overload and indentation
  • Corrosion (fretting, moisture)
  • False brinelling
  • Electric erosion
  • Fracture and cracking
• Lubrication Considerations: Importance of lubricant properties such as viscosity, chemistry, contamination levels, and how changes in these properties can indicate impending failures.
• Sampling Practices: Best practices for oil sampling locations, frequencies, and techniques to ensure accurate, representative test results relevant to bearing condition.
• Integration with Other Monitoring Techniques: Recognizing the roles of vibration monitoring, thermal imaging, and direct inspection in comprehensive machinery health programs.

Applications

• Industrial Machinery Maintenance: Essential for reliability engineers, maintenance supervisors, and plant operators managing equipment such as compressors, gearboxes, pumps, and gas turbines utilizing rolling element ball bearings.
• Predictive and Condition-Based Maintenance Programs: Supports the implementation and optimization of oil analysis as a core tool for early detection of bearing wear and lubricant issues, enabling timely intervention before catastrophic failure.
• Safety and Asset Management: Provides a structured method to enhance safety and extend asset lifecycle by preventing unplanned outages and minimizing downtime.
• OEM and Aftermarket Support: Used by equipment manufacturers and service providers to define oil analysis requirements and advise customers on best practices for bearing health monitoring.

Related Standards

Implementing ASTM D8128-22 often involves referencing additional standards for test methods, terminology, and monitoring practices, such as:

• ASTM D445: Test Method for Kinematic Viscosity of Transparent and Opaque Liquids
• ASTM D7042: Test Method for Dynamic Viscosity and Density of Liquids by Stabinger Viscometer
• ASTM D664: Test Method for Acid Number of Petroleum Products
• ASTM D7414: Condition Monitoring of Oxidation in Petroleum and Hydrocarbon-Based Lubricants by FT-IR
• ASTM D6595: Determination of Wear Metals and Contaminants in Used Lubricating Oils
• ASTM D7596, D7685, D7690: Methods for Particle Counting, Wear Particle Sensor Use, and Analytical Ferrography
• ISO 15243: Rolling bearings - Damage and failures - Terms and causes
• ASTM D7874: Guide for Applying FMEA to In-Service Lubricant Testing

Practical Value

Adopting ASTM D8128-22 enables industrial operators to move beyond generic oil testing, implementing focused analysis to detect and mitigate specific bearing failure risks. This proactive approach supports optimized maintenance intervals, reduced operational costs, and more reliable plant performance-crucial for maximizing uptime in critical industrial sectors. By integrating with existing monitoring technologies and drawing on referenced standards, users can build robust, data-driven lubrication and bearing management programs tailored to their unique operating environment.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D8128 − 22
Standard Guide for
Monitoring Failure Mode Progression in Industrial
Applications with Rolling Element Ball Type Bearings
This standard is issued under the fixed designation D8128; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Oil analysis is a part of condition based maintenance programs. Despite being widely used for
several decades, there is no systematic approach in selecting oil tests based on failure mode analysis.
Most users select tests primarily based on oil degradation criteria, minimizing the potential for
detecting surface damage and limiting the potential benefits of the oil analysis program. This guide
providesjustificationforoilanalysisinindustrialapplicationsfromafailurestandpointtoincludeboth
rolling element bearing wear and fluid deterioration.
1. Scope* mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This guide approaches oil analysis from a failure stand-
point and includes both the rolling element ball type bearing
2. Referenced Documents
wear and fluid deterioration in industrial application.
2.1 ASTM Standards:
1.2 This guide pertains to improving equipment reliability,
D445 Test Method for Kinematic Viscosity of Transparent
reducing maintenance costs and enhancing the condition-based
and Opaque Liquids (and Calculation of Dynamic Viscos-
maintenance program primarily for industrial machinery by
ity)
applying analytical methodology to oil analysis program for
D664 Test Method for Acid Number of Petroleum Products
the purpose of detecting specific failure modes.
by Potentiometric Titration
1.3 This guide reinforces requirements for appropriate
D1500 Test Method forASTM Color of Petroleum Products
assembly,operationwithintheoriginaldesignenvelopeaswell
(ASTM Color Scale)
as the need for condition-based and time-based maintenance.
D4175 Terminology Relating to Petroleum Products, Liquid
1.4 This guide covers the principles of Failure Mode and Fuels, and Lubricants
D6304 Test Method for Determination of Water in Petro-
Effect Analysis (FMEA) as described in Guide D7874 and its
relationship to rolling element ball type bearing wear in leum Products, Lubricating Oils, and Additives by Cou-
lometric Karl Fischer Titration
industrial application and its fluid deterioration.
D6595 Test Method for Determination of Wear Metals and
1.5 This standard does not purport to address all of the
Contaminants in Used Lubricating Oils or Used Hydraulic
safety concerns, if any, associated with its use. It is the
Fluids by Rotating Disc ElectrodeAtomic Emission Spec-
responsibility of the user of this standard to establish appro-
trometry
priate safety, health, and environmental practices and deter-
D7042 Test Method for Dynamic Viscosity and Density of
mine the applicability of regulatory limitations prior to use.
Liquids by Stabinger Viscometer (and the Calculation of
1.6 This international standard was developed in accor-
Kinematic Viscosity)
dance with internationally recognized principles on standard-
D7414 Test Method for Condition Monitoring of Oxidation
ization established in the Decision on Principles for the
in In-Service Petroleum and Hydrocarbon Based Lubri-
Development of International Standards, Guides and Recom-
cants byTrendAnalysis Using FourierTransform Infrared
(FT-IR) Spectrometry
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-
mittee D02.96.04 on Guidelines for In-Services Lubricants Analysis. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved May 1, 2022. Published May 2022. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2017. Last previous edition approved in 2017 as D8128 – 17. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D8128-22. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
D8128 − 22
D7483 TestMethodforDeterminationofDynamicViscosity 3.1.7 dynamic viscosity [η], n—ratio of applied shear stress
and Derived Kinematic Viscosity of Liquids by Oscillat- and the resulting rate of shear.
ing Piston Viscometer
3.1.7.1 Discussion—It is also sometimes called absolute
D7596 Test Method for Automatic Particle Counting and
viscosity. Dynamic viscosity is a measure of the resistance to
Particle Shape Classification of Oils Using a Direct
flow of the liquid at a given temperature. In SI, the unit of
Imaging Integrated Tester
dynamic viscosity is the Pascal·second (Pa·s), often conve-
D7685 Practice for In-Line, Full Flow, Inductive Sensor for
niently expressed as milliPascal·second (mPa·s), which is the
Ferromagnetic and Non-ferromagnetic Wear Debris De-
equivalent of the centipoise (cP) in the centimetre gram second
termination and Diagnostics for Aero-Derivative and Air-
system of units (CGS).
craft Gas Turbine Engine Bearings
3.1.8 effects of failure, n—potential outcome(s) of each
D7690 Practice for Microscopic Characterization of Par-
failure mode on the system or component.
ticles from In-Service Lubricants by Analytical Ferrogra-
3.1.9 elastohydrodynamic lubrication (EHD), n—a condi-
phy
tionwhereextremelyhighfluidinterfacepressuredevelopedin
D7874 Guide for Applying Failure Mode and Effect Analy-
concentrated rolling element contact causes the viscosity of the
sis (FMEA) to In-Service Lubricant Testing
lubricanttoincreasebyseveralordersofmagnitudeandforthe
2.2 ISO Standards:
surfaces to deform them appreciably in proportion to the
ISO 4407 Hydraulic Fluid Power—Fluid contamination—
thickness of a fluid film between the surfaces.
Determination of particulate contamination by the count-
3.1.10 failuredevelopingperiod,FDP,n—periodfromcom-
ing method using an optical microscope
ponent’s incipient failure to functional failure.
ISO 11500 Hydraulic Fluid Power—Determination of the
particulate contamination level of a liquid sample by
3.1.11 failure mode, n—the physical description of the
automatic particle counting using the light-extinction
manner in which failure occurs.
principle
3.1.12 failure mode and effect analysis (FMEA),
ISO 15243 Rolling bearings – Damage and failures – Terms,
n—analytical approach to determine and address methodically
characteristics and causes
all possible system or component failure modes and their
ISO 16232-7 Road Vehicles—Cleanliness of components of
associated causes and effects on system performance.
fluid circuits—Part 7: Particle sizing and counting by
3.1.12.1 Discussion—This approach can be used to evaluate
microscopic analysis
design and track risk-reducing improvements to equipment
ISO 16700 Microbeam analysis—Scanning electron
reliability.
microscopy—Guidelines for calibrating image magnifica-
3.1.13 hydrodynamic lubrication (HD), n—lubrication re-
tion
gime where the load carrying surfaces are separated by a
ISO 24597 Microbeam analysis—Scanning electron
relatively thick film of lubricant formed by a combination of
microscopy—Methods of evaluating image sharpness
surface geometry, surface relative motion, and fluid viscosity.
3. Terminology
3.1.14 kinematic viscosity [ν], n—the ratio of the dynamic
viscosity (η) to the density of the fluid (ρ).
3.1 Definitions:
3.1.14.1 Discussion—In SI, the unit of kinematic viscosity
3.1.1 Fordefinitionsandtermsrelatingtothisguide,referto
is the metre squared per second (m /s), often conveniently
Terminology D4175. Selected terms from these Terminology
expressed as millimetre squared per second (mm /s), which is
Standards are also included here for the benefit of readers.
equivalent of the centistoke (cSt) in the centimetre gram
3.1.2 bearing failure, n—the termination of the bearing’s
second system of units (CGS).
ability to perform its design function.
3.1.3 bearing failure initiation, n—the moment a bearing 3.1.15 severity number [S], n—ranking number that de-
starts to perform outside of its design function measured by scribes the seriousness of the consequences of each failure’s
performance characteristics. modes, causes and effects on potential injury, component or
equipment damage, and system availability.
3.1.4 causes of failure, n—underlying source(s) for each
potential failure mode that can be identified and described by
4. Summary of Guide
analytical testing.
3.1.5 design function, n—function or task that the system or 4.1 This guide is designed to assist users in the condition
assessment of rolling element ball type bearing applications by
components should perform.
selectingoiltestsassociatedwithspecificfailuremodes,causes
3.1.6 detection ability number [D], n—ranking number that
or effects for the purpose of detecting the earliest stage of
describes the ability of a specific fluid test to successfully
failure development.
detectafailuremode’scauseoreffects.Ascaleisusedtograde
detection ability numbers.
4.2 There are a number of different industrial systems with
rolling element bearings. A simple horizontal bearing housing
utilizing rolling element ball type bearings lubricated by oil
splash will be discussed. This is a typical arrangement for
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. many industrial overhang pump applications.
D8128 − 22
4.3 The focus of this guide is to select oil tests capable of 6.3 The main failure modes of rolling element bearings are
detecting and monitoring progression of specific rolling ele- rapid or slow deterioration of the EHD film.
ment ball type bearing failure modes, their causes and effects
6.4 The rapid breakdown of EHD film can be caused by a
as well as lubricating oil deterioration related to these failures.
sudden loss of lubricating oil available for splash lubrication, a
rapid change in bearing operating conditions that is outside the
5. Significance and Use
original design basis, or accidental bearing material disintegra-
tion.
5.1 This guide is intended as a guideline for justification of
oil test selection for monitoring rolling element ball type
6.5 The slow deterioration of EHD oil film can be moni-
bearing conditions in industrial applications. Continuous
tored by permanent sensors mounted on the bearing housing or
benchmarkingagainstsimilarapplicationsisrequiredtoensure
by off-line, periodic oil sample analysis. Based on operating
lessons learned are continuously implemented.
experience several causes are linked to this failure mode.
6.6 Causes of Rolling Element Ball Type Bearing Failures:
5.2 Selection of oil tests for the purpose of detecting rolling
6.6.1 Change in Dynamic Viscosity of the Lubricating
element ball type bearing failure modes requires good under-
Oil—Although under the EHD theory dynamic viscosity value
standing of equipment design, operating requirements and
isreduced(approximatelytothepower0.7),thisoilpropertyis
surrounding conditions. Specifically, detailed knowledge is
still one of the main factors controlling the oil film thickness.
required on bearing design configuration, dimensional
Ingeneral,areductionindynamicviscositywillreduceoilfilm
tolerances, load directions, design limitations, lubrication
thickness. Under severe transient conditions, reduction of the
mechanisms, lubricant characteristics, and metallurgy of lubri-
oil film thickness may change the lubricating regime from
cated surfaces including bearing cages. Equipment criticality
EHD to mixed or boundary, resulting in an increased risk of
and accessibility as well as application of other monitoring
bearing surface contact and wear. Under the opposite condition
techniques (for example, vibration, ultrasound or thermal
whenthedynamicviscosityistoohigh,anincreaseindragand
images) are also critical information in this analysis process. In
friction will result in local heat generation. This may increase
addition, detailed knowledge on the lubricating oil is para-
the rate of chemical reaction within the oil film. In condition-
mount.
based maintenance programs for industrial applications, kine-
5.3 To properly apply the FMEA methodology users must
matic viscosity at 40 °C (or occasionally at 100 °C) is used to
understand the changes the system may encounter during all
measurethisproperty.Theassumptionisthatinmostindustrial
operating modes, their impact on design functions and avail-
applications, lubricant density is not significantly changed in
able monitoring techniques capable of detecting these changes.
the measured temperature of interest (for example, 40 °C or
To assist this approach, Section 6 will provide extensive
100 °C) and trending kinematic viscosity can provide adequate
descriptions on the rolling element ball type bearing failure
prediction of the lubricant’s ability to form a reliable and
modes, their causes and effects.
sustainable EHD oil film. However, newer methods exist that
will measure dynamic viscosity directly (Test Method D7042).
5.4 It is recognized that in most industrial applications
vibration monitoring is the primary condition monitoring These methods may in time become commonly used in this
approach.
technique applied to detect failure modes, causes and effects in
rolling element ball type bearings—while oil analysis is 6.6.2 Deterioration of Lubricating Oil Chemistry—The
EHD lubrication condition will also depend on the complex
primarily used to monitor the lubricating oil properties. In the
recentyears,however,thereisatrendtowardusingoilanalysis relationship between properties of oil-to-metal adhesion and
oil-to-oil cohesion. Applying a constant shear stress on the
in order to provide earlier detection of some failures of rolling
element ball type bearings. This is particularly applicable to lubricating oil film may lead to physical damage to the
complex dynamic systems such as compressors, gearboxes and lubricant molecules. The presence of atmospheric oxygen may
some gas turbines where obtaining vibration spectra and their initiate chemical reactions such as oxidation. High temperature
analysis may be more difficult. and pressure will accelerate these reactions and cause thermal
breakdown of lubricant molecules. Finally, lubricating oil will
also deteriorate by the additive depletion process (for example,
6. Failure Modes and Their Effects for Rolling Element
due to expected performance). The depletion rate would
Ball Type Bearing Applications
depend on the additive type, applications, and operating
6.1 During normal operation, rolling element bearings op-
conditions. The consequences of these chemical changes will
erate primarily in the elastohydrodynamic (EHD) lubrication
influenceseveralcriticalpropertiessuchascohesion,adhesion,
regime. However, in typical rolling element ball bearing
surface tension, etc. Some visible changes might include an
application the lubrication between the rolling element and
increase in foaming characteristics, air release, sludge and
cage is usually controlled by the hydrodynamic (HD) lubrica-
varnish formation, or reduced oil solubility characteristics.
tion principle.
6.6.3 Increase in Gaseous, Liquid, and Solid Particle
6.2 The EHD oil film thickness depends on the elastic Contamination—All three contaminant types will affect the
deformation of the rolling materials, bearing size, rolling EHD oil film but in different mechanisms.
speed, dynamic viscosity of the lubricating oil at operating 6.6.3.1 An excessive amount of undissolved gas bubbles in
temperature and pressure, as well as the pressure-viscosity the oil may weaken the load carrying capacity of the lubricat-
coefficient. ing film. If the gas is reactive it can promote chemical
D8128 − 22
degradation of the lubricant which may change the physical ring raceway, misalignment, etc. All of these occurred during
characteristics of the oil. bearing installation and will have significant impact on bearing
performance and life.
6.6.3.2 A large amount of liquid contaminants, particularly
6.6.8 Manufacturing Defects—Due to significant improve-
those having significantly different viscosity or density, may
mentintherollingelementballbearingmanufacturingprocess,
influence the dynamic viscosity. In addition, some contaminant
defects related to manufacturing processes have significantly
may react with the lubricant affecting its performance charac-
been minimized. However, this cause cannot be completely
teristics. An example is free water, which may not support the
eliminated from the root cause analysis although a typical oil
external load acting on the bearing. It could also hydrolyze
conditionmonitoringprogramisnotthebestapproachtodetect
some of the additives, affecting their performance or cause
this cause.
rusting of bearing component.
6.7 Effects of Rolling Element Ball Type Bearing Failures:
6.6.3.3 The presence of solid particles is harmful in rolling
6.7.1 Inadditiontothepresenteddifferentfailuremodesand
element bearing applications due to significantly smaller oil
causes, there are several failure effects of rolling element ball
film thickness and high interface pressure between rolling
type bearings.
elements and raceway. Solid particles usually cause damage to
6.7.2 In technical literature there are several different clas-
rolling element surfaces by forming small indentations, which
sificationsofballbearingwearmechanisms.Forthepurposeof
change the local surface fatigue leading to bearing failure.
this guide, Table 1 presents a simplified wear classification of
6.6.4 Abnormal Load in Contact Zones—Thiscanbecaused
rolling element ball type bearings, which will be discussed in
by excessive thrust load, excessive internal preload, pinched
this guide.
outer ring, outer or inner ring misaligned.
6.7.3 Bearing Surface Damage due to Subsurface Fatigue—
6.6.4.1 Excessive thrust load may occur when there is axial
Subsurface fatigue is a form of wear that occurs after many
overload from the machine resulting in very high stress which
cycles of high-stress flexing of the metal.This causes cracks in
can cause metal fatigue.
the subsurface of the metal, which then propagate to the
6.6.4.2 Excessive internal preload may occur when there is
surface, resulting in a piece of surface metal being removed or
no internal clearance in mounting bearing resulting in wider
delaminated. It begins with inclusions or faults in the bearing
contact in the stationary ring.
metal below the surface. Solid particles in the EHD oil film
6.6.4.3 A pinched outer ring occurs when outer ring has
which produce dents on the raceway may also initiate fatigue
been forced out-of-run during installation resulting in rolling damage for bearings in motion. These round-bottomed dents
elements making contact with the outer ring raceway in more
often have a raised berm around their edges. The raised berm
than one load zone. This may distort the housing which in turn of metal generates stress concentrations below the load carry-
will pinch the outer ring. ing surface, which after time causes crack. As the rolling
elements pass over the cracks, fragments of material break
6.6.4.4 The outer ring is misaligned when it is not perpen-
away and this is known as flaking or spalling.
dicular to the centerline of the shaft.As a result, the outer ring
6.7.4 Bearing Surface Damage due to Surface Stress—If the
could be cocked out of alignment and may result in premature
lubricating film between raceway and the rolling elements
bearing failure.
become too thin, the peaks of the surface asperities will come
6.6.4.5 The inner ring misalignment may force the rolling
elements making contacts with both the inner and outer ring
raceways in a diagonal pattern on the sides of the raceways.
This causes very high stress which can result in metal fatigue
TABLE 1 Wear Classification of Rolling Element Ball Type
and premature bearing failure.
Bearings
6.6.4.6 If the radial and axial loading of the ball bearing is
Failure Mode Effects of Rolling Element Bearings
too light, this can lead to ball smearing.
6.6.5 Defective Bearing Seat on Shaft—This condition oc- Wear Classification Effects
curs when the inner ring does not have a sufficient press fit on Subsurface fatigue
Fatigue
Surface distress
a shaft allowing slight movement
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D8128 − 17 D8128 − 22
Standard Guide for
Monitoring Failure Mode Progression in Industrial
Applications with Rolling Element Ball Type Bearings
This standard is issued under the fixed designation D8128; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Oil analysis is a part of condition based maintenance programs. Despite being widely used for
several decades, there is no systematic approach in selecting oil tests based on failure mode analysis.
Most users select tests primarily based on oil degradation criteria, minimizing the potential for
detecting surface damage and limiting the potential benefits of the oil analysis program. This guide
provides justification for oil analysis in industrial applications from a failure standpoint to include both
rolling element bearing wear and fluid deterioration.
1. Scope Scope*
1.1 This guide approaches oil analysis from a failure standpoint and includes both the rolling element ball type bearing wear and
fluid deterioration in industrial application.
1.2 This guide pertains to improving equipment reliability, reducing maintenance costs and enhancing the condition-based
maintenance program primarily for industrial machinery by applying analytical methodology to oil analysis program for the
purpose of detecting specific failure modes.
1.3 This guide reinforces requirements for appropriate assembly, operation within the original design envelope as well as the need
for condition-based and time-based maintenance.
1.4 This guide covers the principles of Failure Mode and Effect Analysis (FMEA) as described in Guide D7874 and its relationship
to rolling element ball type bearing wear in industrial application and its fluid deterioration.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.96.04 on Guidelines for In-Services Lubricants Analysis.
Current edition approved Oct. 1, 2017May 1, 2022. Published October 2017May 2022. Originally approved in 2017. Last previous edition approved in 2017 as D8128 – 17.
DOI: 10.1520/D8128-17.10.1520/D8128-22.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8128 − 22
2. Referenced Documents
2.1 ASTM Standards:
D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
D664 Test Method for Acid Number of Petroleum Products by Potentiometric Titration
D1500 Test Method for ASTM Color of Petroleum Products (ASTM Color Scale)
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
D6304 Test Method for Determination of Water in Petroleum Products, Lubricating Oils, and Additives by Coulometric Karl
Fischer Titration
D6595 Test Method for Determination of Wear Metals and Contaminants in Used Lubricating Oils or Used Hydraulic Fluids by
Rotating Disc Electrode Atomic Emission Spectrometry
D7042 Test Method for Dynamic Viscosity and Density of Liquids by Stabinger Viscometer (and the Calculation of Kinematic
Viscosity)
D7414 Test Method for Condition Monitoring of Oxidation in In-Service Petroleum and Hydrocarbon Based Lubricants by
Trend Analysis Using Fourier Transform Infrared (FT-IR) Spectrometry
D7483 Test Method for Determination of Dynamic Viscosity and Derived Kinematic Viscosity of Liquids by Oscillating Piston
Viscometer
D7596 Test Method for Automatic Particle Counting and Particle Shape Classification of Oils Using a Direct Imaging Integrated
Tester
D7685 Practice for In-Line, Full Flow, Inductive Sensor for Ferromagnetic and Non-ferromagnetic Wear Debris Determination
and Diagnostics for Aero-Derivative and Aircraft Gas Turbine Engine Bearings
D7690 Practice for Microscopic Characterization of Particles from In-Service Lubricants by Analytical Ferrography
D7874 Guide for Applying Failure Mode and Effect Analysis (FMEA) to In-Service Lubricant Testing
2.2 ISO Standards:
ISO 4407 Hydraulic Fluid Power—Fluid contamination—Determination of particulate contamination by the counting method
using an optical microscope
ISO 11500 Hydraulic Fluid Power—Determination of the particulate contamination level of a liquid sample by automatic
particle counting using the light-extinction principle
ISO 15243 Rolling bearings – Damage and failures – Terms, characteristics and causes
ISO 16232-7 Road Vehicles—Cleanliness of components of fluid circuits—Part 7: Particle sizing and counting by microscopic
analysis
ISO 16700 Microbeam analysis—Scanning electron microscopy—Guidelines for calibrating image magnification
ISO 24597 Microbeam analysis—Scanning electron microscopy—Methods of evaluating image sharpness
3. Terminology
3.1 Definitions:
3.1.1 For definitions and terms relating to this guide, refer to Terminology D4175. Selected terms from these Terminology
Standards are also included here for the benefit of readers.
3.1.2 bearing failure, n—the termination of the bearing’s ability to perform its design function.
3.1.3 bearing failure initiation, n—the moment a bearing starts to perform outside of its design function measured by performance
characteristics.
3.1.4 causes of failure, n—underlying source(s) for each potential failure mode that can be identified and described by analytical
testing.
3.1.5 design function, n—function or task that the system or components should perform.
3.1.6 detection ability number [D], n—ranking number that describes the ability of a specific fluid test to successfully detect a
failure mode’s cause or effects. A scale is used to grade detection ability numbers.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
D8128 − 22
3.1.7 dynamic viscosity [η], n—ratio of applied shear stress and the resulting rate of shear.
3.1.7.1 Discussion—
It is also sometimes called absolute viscosity. Dynamic viscosity is a measure of the resistance to flow of the liquid at a given
temperature. In SI, the unit of dynamic viscosity is the Pascal·second (Pa·s), often conveniently expressed as milliPascal·second
(mPa·s), which hasis the English system equivalent of the centipoise (cP).(cP) in the centimetre gram second system of units
(CGS).
3.1.8 effects of failure, n—potential outcome(s) of each failure mode on the system or component.
3.1.9 elastohydrodynamic lubrication (EHD), n—a condition where extremely high fluid interface pressure developed in
concentrated rolling element contact causes the viscosity of the lubricant to increase by several orders of magnitude and for the
surfaces to deform them appreciably in proportion to the thickness of a fluid film between the surfaces.
3.1.10 failure-developing period (FDP), failure developing period, FDP, n—period from component’s incipient failure to
functional failure.
3.1.11 failure mode, n—the physical description of the manner in which failure occurs.
3.1.12 failure mode and effect analysis (FMEA), n—analytical approach to determine and address methodically all possible system
or component failure modes and their associated causes and effects on system performance.
3.1.12.1 Discussion—
This approach can be used to evaluate design and track risk-reducing improvements to equipment reliability.
3.1.13 hydrodynamic lubrication (HD), n—lubrication regime where the load carrying surfaces are separated by a relatively thick
film of lubricant formed by a combination of surface geometry, surface relative motion, and fluid viscosity.
3.1.14 kinematic viscosity [ν], n—the ratio of the dynamic viscosity (η) to the density of the fluid (ρ).
3.1.14.1 Discussion—
In SI, the unit of kinematic viscosity is mthe metre squared per second (m /s,/s), often conveniently expressed as mmmillimetre
squared per second (mm /s, which has the English system /s), which is equivalent of the centistoke (cSt).(cSt) in the centimetre
gram second system of units (CGS).
3.1.15 severity number [S], n—ranking number that describes the seriousness of the consequences of each failure’s modes, causes
and effects on potential injury, component or equipment damage, and system availability.
4. Summary of Guide
4.1 This guide is designed to assist users in the condition assessment of rolling element ball type bearing applications by selecting
oil tests associated with specific failure modes, causes or effects for the purpose of detecting the earliest stage of failure
development.
4.2 There are a number of different industrial systems with rolling element bearings. A simple horizontal bearing housing utilizing
rolling element ball type bearings lubricated by oil splash will be discussed. This is a typical arrangement for many industrial
overhang pump applications.
4.3 The focus of this guide is to select oil tests capable of detecting and monitoring progression of specific rolling element ball
type bearing failure modes, their causes and effects as well as lubricating oil deterioration related to these failures.
5. Significance and Use
5.1 This guide is intended as a guideline for justification of oil test selection for monitoring rolling element ball type bearing
conditions in industrial applications. Continuous benchmarking against similar applications is required to ensure lessons learned
are continuously implemented.
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5.2 Selection of oil tests for the purpose of detecting rolling element ball type bearing failure modes requires good understanding
of equipment design, operating requirements and surrounding conditions. Specifically, detailed knowledge is required on bearing
design configuration, dimensional tolerances, load directions, design limitations, lubrication mechanisms, lubricant characteristics,
and metallurgy of lubricated surfaces including bearing cages. Equipment criticality and accessibility as well as application of other
monitoring techniques (for example, vibration, ultrasound or thermal images) are also critical information in this analysis process.
In addition, detailed knowledge on the lubricating oil is paramount.
5.3 To properly apply the FMEA methodology users must understand the changes the system may encounter during all operating
modes, their impact on design functions and available monitoring techniques capable of detecting these changes. To assist this
approach, Section 6 will provide extensive descriptions on the rolling element ball type bearing failure modes, their causes and
effects.
5.4 It is recognized that in most industrial applications vibration monitoring is the primary condition monitoring technique applied
to detect failure modes, causes and effects in rolling element ball type bearings—while oil analysis is primarily used to monitor
the lubricating oil properties. In the recent years, however, there is a trend toward using oil analysis in order to provide earlier
detection of some failures of rolling element ball type bearings. This is particularly applicable to complex dynamic systems such
as compressors, gearboxes and some gas turbines where obtaining vibration spectra and their analysis may be more difficult.
6. Failure Modes and Their Effects for Rolling Element Ball Type Bearing Applications
6.1 During normal operation, rolling element bearings operate primarily in the elastohydrodynamic (EHD) lubrication regime.
However, in typical rolling element ball bearing application the lubrication between the rolling element and cage is usually
controlled by the hydrodynamic (HD) lubrication principle.
6.2 The EHD oil film thickness depends on the elastic deformation of the rolling materials, bearing size, rolling speed, dynamic
viscosity of the lubricating oil at operating temperature and pressure, as well as the pressure-viscosity coefficient.
6.3 The main failure modes of rolling element bearings are rapid or slow deterioration of the EHD film.
6.4 The rapid breakdown of EHD film can be caused by a sudden loss of lubricating oil available for splash lubrication, a rapid
change in bearing operating conditions that is outside the original design basis, or accidental bearing material disintegration.
6.5 The slow deterioration of EHD oil film can be monitored by permanent sensors mounted on the bearing housing or by off-line,
periodic oil sample analysis. Based on operating experience several causes are linked to this failure mode.
6.6 Causes of Rolling Element Ball Type Bearing Failures:
6.6.1 Change in Dynamic Viscosity of the Lubricating Oil—Although under the EHD theory dynamic viscosity value is reduced
(approximately to the power 0.7), this oil property is still one of the main factors controlling the oil film thickness. In general, a
reduction in dynamic viscosity will reduce oil film thickness. Under severe transient conditions, reduction of the oil film thickness
may change the lubricating regime from EHD to mixed or boundary, resulting in an increased the risk of bearing surface contact
and wear. Under the opposite condition when the dynamic viscosity is too high, an increase in drag and friction will result in local
heat generation. This may increase the rate of chemical reaction within the oil film. In condition-based maintenance programs for
industrial applications, kinematic viscosity at 40 °C (or occasionally at 100 °C) is used to measure this property. The assumption
is that in most industrial applications, lubricant density is not significantly changed in the measured temperature of interest (for
example, 40 °C or 100 °C) and trending kinematic viscosity can provide adequate prediction of the lubricant’s ability to form a
reliable and sustainable EHD oil film. However, newer methods exist that will measure dynamic viscosity directly (Test Method
D7042). These methods may in time become commonly used in this approach.
6.6.2 Deterioration of Lubricating Oil Chemistry—The EHD lubrication condition will also depend on the complex relationship
between properties of oil-to-metal adhesion and oil-to-oil cohesion. Applying a constant shear stress on the lubricating oil film may
lead to physical damage to the lubricant molecules. The presence of atmospheric oxygen may initiate chemical reactions such as
oxidation. High temperature and pressure will accelerate these reactions and cause thermal breakdown of lubricant molecules.
Finally, lubricating oil will also deteriorate by the additive depletion process (for example, due to expected performance). The
depletion rate would depend on the additive type, applications, and operating conditions. The consequences of these chemical
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changes will influence several critical properties such as cohesion, adhesion, surface tension, etc. Some visible changes might
include an increase in foaming characteristics, air release, sludge and varnish formation, or reduced oil solubility characteristics.
6.6.3 Increase in Gaseous, Liquid, and Solid Particle Contamination—All three contaminant types will affect the EHD oil film
but in different mechanisms.
6.6.3.1 An excessive amount of undissolved gas bubbles in the oil may weaken the load carrying capacity of the lubricating film.
If the gas is reactive it can promote chemical degradation of the lubricant which may change the physical characteristics of the
oil.
6.6.3.2 A large amount of liquid contaminants, particularly those having significantly different viscosity or density, may influence
the dynamic viscosity. In addition, some contaminant may react with the lubricant affecting its performance characteristics. An
example is free water, which may not support the external load acting on the bearing. It could also hydrolyze some of the additives,
affecting their performance or cause rusting of bearing component.
6.6.3.3 The presence of solid particles is harmful in rolling element bearing applications due to significantly smaller oil film
thickness and high interface pressure between rolling elements and raceway. Solid particles usually cause damage to rolling
element surfaces by forming small indentations, which change the local surface fatigue leading to bearing failure.
6.6.4 Abnormal Load in Contact Zones—This can be caused by excessive thrust load, excessive internal preload, pinched outer
ring, outer or inner ring misaligned.
6.6.4.1 Excessive thrust load may occur when there is axial overload from the machine resulting in very high stress which can
cause metal fatigue.
6.6.4.2 Excessive internal preload may occur when there is no internal clearance in mounting bearing resulting in wider contact
in the stationary ring.
6.6.4.3 A pinched outer ring occurs when outer ring has been forced out-of-run during installation resulting in rolling elements
making contact with the outer ring raceway in more than one load zone. This may distort the housing which in turn will pinch the
outer ring.
6.6.4.4 The outer ring is misaligned when it is not perpendicular to the centerline of the shaft. As a result, the outer ring could
be cocked out of alignment and may result in premature bearing failure.
6.6.4.5 The inner ring misalignment may force the rolling elements making contacts with both the inner and outer ring raceways
in a diagonal pattern on the sides of the raceways. This causes very high stress which can result in metal fatigue and premature
bearing failure.
6.6.4.6 If the radial and axial loading of the ball bearing is too light, this can lead to ball smearing.
6.6.5 Defective Bearing Seat on Shaft—This condition occurs when the inner ring does not have a sufficient press fit on a shaft
allowing slight movement of low amplitude resulting in fretting corrosion.
6.6.6 Defective Bearing Seat in Housing—This condition occurs when the bearing outside diameter and the housing bore do not
make intimate contact allowing slight movements of low amplitude. This will result in fretting corrosion forming a reddish
brown-black oxide and significant discoloration of lubricating oil. If the bearing seat is too tight this condition can cause
overloading.
6.6.7 Improper Mounting—There are several conditions resulting from improper mounting causing premature bearing failures.
These may include indentation at the top side of the ball groove, spalled or fractured outer ring, scoring on the inner ring raceway,
misalignment, etc. All of these occurred during bearing installation and will have significant impact on bearing performance and
life.
6.6.8 Manufacturing Defects—Due to significant improvement in the rolling element ball bearing manufacturing process, defects
related to manufacturing processes have significantly been minimized. However, this cause cannot be completely eliminated from
the root cause analysis although a typical oil condition monitoring program is not the best approach to detect this cause.
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6.7 Effects of Rolling Element Ball Type Bearing Failures:
6.7.1 In addition to the presented different failure modes and causes, there are several failure effects of rolling element ball type
bearings.
6.7.2 In technical literature there are several different classifications of ball bearing wear mechanisms. For the purpose of this
guide, Table 1 presents a simplified wear classification of rolling element ball type bearings, which will be discussed in this guide.
6.7.3 Bearing Surface Damage due to Subsurface Fatigue—Subsurface fatigue is a form of wear that occurs after many cycles of
high-stress flexing of the metal. This causes cracks in the subsurface of the metal, which then propagate to the surface, resulting
in a piece of surface metal being removed or delaminated. It begins with inclusio
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