ASTM D5183-21a

Standard Test Method for Determination of the Coefficient of Friction of Lubricants Using the Four-Ball Wear Test Machine

SIGNIFICANCE AND USE
5.1 This test method can be used to determine the coefficient of friction of lubricating fluids under the prescribed test conditions. The user of this test method should determine to his own satisfaction whether results of this test method correlate with field performance or other bench test machines.
SCOPE
1.1 This test method covers a procedure for determining the coefficient of friction by means of the Four-Ball Wear Test Machine.2  
1.2 The values stated in either SI units or in the former cm-kgf metric units are to be regarded separately as the standard. Within the text the cm-kgf units are shown in parentheses. The values stated in each system are not exact equivalents, therefore each system must be used independently of the other. Combining values from the two systems can result in nonconformance to specification.  
1.3 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. Specific warning statements are given in 7.3 and 7.4.  
1.4 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: 31-Oct-2021
• ICS: 75.100 - Lubricants, industrial oils and related products
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.L0.11 - Tribological Properties of Industrial Fluids and Lubricates

Relations

• Refers: ASTM D4172-94(2016) - Standard Test Method for Wear Preventive Characteristics of Lubricating Fluid (Four-Ball Method)
• Effective Date: 01-Jan-2016
• Refers: ASTM D4172-94(2010) - Standard Test Method for Wear Preventive Characteristics of Lubricating Fluid (Four-Ball Method)
• Effective Date: 01-May-2010
• Refers: ASTM D4172-94(2004) - Standard Test Method for Wear Preventive Characteristics of Lubricating Fluid (Four-Ball Method)
• Effective Date: 01-Nov-2004
• Refers: ASTM D4172-94(2004)e1 - Standard Test Method for Wear Preventive Characteristics of Lubricating Fluid (Four-Ball Method)
• Effective Date: 01-Nov-2004
• Refers: ASTM D4172-94(1999) - Standard Test Method for Wear Preventive Characteristics of Lubricating Fluid (Four-Ball Method)
• Effective Date: 10-Nov-1999

Overview

ASTM D5183-21a - Standard Test Method for Determination of the Coefficient of Friction of Lubricants Using the Four-Ball Wear Test Machine provides a systematic procedure to measure the coefficient of friction of lubricating fluids under controlled conditions. Developed by ASTM International, this widely recognized standard is critical for laboratories, manufacturers, and quality control professionals in the petroleum and lubrication industries. The test utilizes a Four-Ball Wear Test Machine to evaluate how well lubricants reduce friction between metal surfaces, offering an essential metric for lubricant performance and formulation.

Key Topics

• Purpose: Provides a procedure to determine the coefficient of friction for lubricating fluids, helping evaluate lubricant effectiveness.
• Test Apparatus: Involves the use of the Four-Ball Wear Test Machine, a specialized instrument for measuring friction and wear characteristics of lubricants.
• Test Methodology:
  • Three steel balls are clamped together and coated with a specified lubricant.
  • A fourth ball is pressed against these balls under controlled temperature and load while rotating.
  • The coefficient of friction is measured at regular intervals as the test load increases.
• Unit Systems: Both SI units and cm-kgf metric units are provided. Each system must be used independently to maintain compliance.
• Results Evaluation: The test results provide quantitative data on wear scar diameter and coefficient of friction, critical for performance assessment.

Applications

ASTM D5183-21a is extensively used across various industries where lubricants play a key role in equipment reliability and performance. Notable application areas include:

• Lubricant Development and Quality Assurance: Manufacturers use this method to compare formulations, monitor product consistency, and ensure performance expectations are met.
• Comparative Performance Studies: Enables direct benchmarking of different lubricants’ friction-reducing properties under identical conditions.
• Research and Development: Supports the design and optimization of advanced lubricants for demanding applications in automotive, industrial, and aerospace sectors.
• Compliance and Specification: Helps meet industry requirements and supports procurement decisions by providing a standardized friction metric.
• Failure Analysis: Assists in identifying issues related to lubricant performance in systems experiencing excessive wear or equipment failure.

Related Standards

Several industry standards complement ASTM D5183-21a for a thorough assessment of lubricants’ tribological properties and to maintain quality in testing processes:

• ASTM D4172: Test Method for Wear Preventive Characteristics of Lubricating Fluid (Four-Ball Method), focusing on wear preventive attributes.
• ANSI/ABMA/ISO 3290-1:2014: Specifications for steel balls used in rolling bearings, relevant for compliance with test apparatus requirements.
• Other Tribological Test Methods: Standards devoted to wear testing, load-carrying capacity, and lubrication properties, such as those for extreme pressure (EP) testing.

By following ASTM D5183-21a, organizations gain accurate, comparable, and reproducible data on the coefficient of friction for lubricants, driving improvements in product quality, safety, and equipment longevity. This standard supports conformity to internationally recognized best practices and enhances confidence in lubricant performance claims. For professionals focused on reliability, efficiency, and regulatory compliance, ASTM D5183-21a remains a cornerstone resource in tribology testing.

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: D5183 − 21a
Standard Test Method for
Determination of the Coefficient of Friction of Lubricants
Using the Four-Ball Wear Test Machine
This standard is issued under the fixed designation D5183; 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.
1. Scope* Lubricating Fluid (Four-Ball Method)
1.1 This test method covers a procedure for determining the 2.2 ANSI/ABMA/ISO Standard:
3290-1-2014 Rolling Bearings – Balls – Part 1: Steel Balls
coefficient of friction by means of the Four-Ball Wear Test
Machine.
3. Terminology
1.2 The values stated in either SI units or in the former
3.1 Definitions:
cm-kgf metric units are to be regarded separately as the
3.1.1 coeffıcient of friction, (µ), n—theratioofthetangential
standard. Within the text the cm-kgf units are shown in
force that is needed to start or to maintain uniform relative
parentheses. The values stated in each system are not exact
motion between two contacting surfaces to the perpendicular
equivalents, therefore each system must be used independently
force holding them in contact.
of the other. Combining values from the two systems can result
in nonconformance to specification.
4. Summary of Test Method
1.3 This standard does not purport to address all of the
4.1 Three12.7 mm(0.5 in.)diametersteelballsareclamped
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- together and covered with 10 mL of the wear-in lubricant. A
fourth 12.7 mm diameter ball, referred to as the “top ball” is
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. pressed with a force of 392 N (40 kgf) into the cavity formed
by the three clamped balls for three-point contact. The tem-
Specific warning statements are given in 7.3 and 7.4.
1.4 This international standard was developed in accor- perature of the wear-in lubricant is regulated at 75 °C (167 °F),
and then, the top ball is rotated at 600 r⁄min for 60 min.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4.2 Fluid is discarded and balls cleaned. The wear scar
Development of International Standards, Guides and Recom-
diameter on each of the lower three balls is examined. If the
mendations issued by the World Trade Organization Technical
wear scars average 0.67 mm 6 0.03 mm, (0.026 in. 6
Barriers to Trade (TBT) Committee.
0.001 in.) then the 10 mL of test fluid is added to the ball cup
with the worn-in test balls in place. The temperature of the test
2. Referenced Documents
lubricant is regulated at 75 °C (167 °F) and the top ball is
2.1 ASTM Standards: rotated at 600 r⁄min at 98.1 N (10 kgf) for 10 min.
D4172 Test Method for Wear Preventive Characteristics of
4.3 The load is then increased by 98.1 N (10 kgf) at the end
of each successive 10 min interval up to the point where the
frictional trace indicates incipient seizure. The coefficient of
This test method is under the jurisdiction of ASTM Committee D02 on
friction is measured at the end of each 10 min interval.
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.L0.11 on Tribological Properties of Industrial Fluids and
Lubricates.
5. Significance and Use
Current edition approved Nov. 1, 2021. Published January 2022. Originally
5.1 Thistestmethodcanbeusedtodeterminethecoefficient
approved in 1991. Last previous edition approved in 2021 as D5183 – 21. DOI:
10.1520/D5183-21A.
of friction of lubricating fluids under the prescribed test
The sole source of supply of the Four-Ball Wear Test Machine known to the
conditions.Theuserofthistestmethodshoulddeterminetohis
committee at this time is Falex Corp., 1020 Airpark Dr., Sugar Grove, IL 60554. If
own satisfaction whether results of this test method correlate
you are aware of alternative suppliers, please provide this information to ASTM
with field performance or other bench test machines.
International Headquarters. Your comments will receive careful consideration at a
meeting of the responsible technical committee, which you may attend.
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 Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
*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
D5183 − 21a
FIG. 1 Schematic of a Four-Ball Wear Test Machine
6. Apparatus
6.1 Four-Ball Test Machine —See Figs. 1-3.
NOTE 1—It is important to distinguish between the Four-Ball E.P. and
theFour-BallWearTestMachine(seeTestMethodD4172).TheFour-Ball
E.P.Test Machine is designed for testing under heavier loads and lacks the
sensitivity necessary for wear tests.
6.2 Microscope, capable of measuring the diameters of the
scars produced on the three balls to an accuracy of 0.01 mm
without removal from the ball test cup.
6.3 Test Balls, chrome alloy steel, made fromAISI Standard
Steel No. E-52100, with diameter of 12.7 mm (0.5 in.) Grade
25 EP (extra polish). Such balls are described in ANSI
Specifications 3290-1-2014. The extra-polish finish is not
described in that specification. The Rockwell C hardness shall
be 64 to 66, a closer limit than is found in the ANSI
FIG. 2 Falex Variable—Speed Four-Ball Wear Test Machine
requirement.
7. Reagents and Materials
8. Preparation of Apparatus
7.1 Purity of Reagents—Reagent grade chemicals shall be
8.1 Set up the drive of the machine to obtain a spindle speed
used in all tests. Unless otherwise indicated, it is intended that
of 600 r⁄min 6 30 r⁄min.
all reagents conform to the specifications of the Committee on
8.2 Set temperature regulator to produce a test-oil tempera-
Analytical Reagents of the American Chemical Society where
such specifications are available. Other grades may be used, ture of 75 °C 6 2 °C (167 °F 6 4 °F).
provided it is first ascertained that the reagent is of sufficiently
8.3 Ifanautomatictimerisusedtoterminateatest,itshould
high purity to permit its use without lessening the accuracy of
becheckedfortherequired 61 minaccuracyat60 minelapsed
the determination.
time, and 610 s at 10 min elapsed time.
7.2 Wear-In Lubricant, white oil having a viscosity at 40 °C
8.4 The loading mechanism should be balanced to a zero
of 24.3 cSt to 26.1 cSt (100 °F of 125/135 SUS). It should be
reading with all parts and test oil in place. To demonstrate
percolated through activated alumina to remove any residual
proper precision an addition or subtraction of 2.0 N (0.2 kgf)
impurities.
should be detectable in imbalance. Determination of accuracy
7.3 Acetone—(Warning—Flammable. Health hazard.) of loading at 147 N and 392 N (15 kgf and 40 kgf) is difficult
and generally limited to careful measurement of lever-arm
7.4 n-Heptane—(Warning—Flammable. Health hazard.)
ratios and weights or piston diameter and pressure gauge
calibration.
NOTE 2—Because of differences in the construction of the various
The Four-Ball Wear Test Machine and the Falex Multi-Specimen Friction and
machines on which the four-ball can be made, the manufacturer’s
Wear Test Machine, both made by Falex Corp., 1020 Airpark Dr., Sugar Grove, IL
instructions should be consulted for proper machine set up and operation.
60554 have been found satisfactory for this purpose. This company can also furnish
a microscope with a special base to measure the wear scars without removing the
ballsfromthetest-oilcup.DiscontinuedmodelsoftheFour-BallWearTestMachine 9. Conditioning
made by Precision Scientific Co. and Roxana Machine Works are also satisfactory.
9.1 Test Conditions—See Table 1.
ACS Reagent Chemicals, Specifications and Procedures for Reagents and
Standard-Grade Reference Materials, American Chemical Society, Washington,
DC. For suggestions on the testing of reagents not listed by theAmerican Chemical 10. Procedure
Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset,
10.1 Thoroughly clean four test balls, clamping parts for
U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharma-
copeial Convention, Inc. (USPC), Rockville, MD. upper and lower balls and the ball cup by first soaking in
D5183 − 21a
FIG. 3 Falex Multi-Specimen Friction and Wear Test Machine
TABLE 1 Test Conditions
10.6 Turn on the heaters and set controls to obtain 75 °C 6
Wear-In Test 2 °C (167 °F 6 4 °F). Heater voltage or offset on proportional
Temperature 75 °C ± 2 °C 75 °C ± 2 °C controllers should be capable of bringing stabilized tempera-
(167 °F ± 4 °F) (167 °F ± 4 °F)
ture within the prescribed limits.
Speed 600 r/min 600 r/min
Duration 60 min 10 min
10.7 When the test temperature is reached, start the drive
Load 392 N (40 kgf) per 60 min 98.1 N (10 kgf) per 10
...

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: D5183 − 21 D5183 − 21a
Standard Test Method for
Determination of the Coefficient of Friction of Lubricants
Using the Four-Ball Wear Test Machine
This standard is issued under the fixed designation D5183; 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.
1. Scope*
1.1 This test method covers a procedure for determining the coefficient of friction by means of the Four-Ball Wear Test Machine.
1.2 The values stated in either SI units or in the former cm-kgf metric units are to be regarded separately as the standard. Within
the text the cm-kgf units are shown in parentheses. The values stated in each system are not exact equivalents, therefore each
system must be used independently of the other. Combining values from the two systems can result in nonconformance to
specification.
1.3 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. Specific warning statements are given in 7.3 and 7.4.
1.4 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.
2. Referenced Documents
2.1 ASTM Standards:
D4172 Test Method for Wear Preventive Characteristics of Lubricating Fluid (Four-Ball Method)
2.2 ANSIANSI/ABMA/ISO Standard:
B3.123290-1-2014 Specification for Metal Rolling Bearings – Balls – Part 1: Steel Balls
3. Terminology
3.1 Definitions:
3.1.1 coeffıcient of friction, (μ)—(μ), n—the ratio of the tangential force that is needed to start or to maintain uniform relative
motion between two contacting surfaces to the perpendicular force holding them in contact.
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.L0.11 on Tribological Properties of Industrial Fluids and Lubricates.
Current edition approved May 1, 2021Nov. 1, 2021. Published June 2021January 2022. Originally approved in 1991. Last previous edition approved in 20162021 as D5183
– 05 (2016). 21. DOI: 10.1520/D5183-21.10.1520/D5183-21A.
The sole source of supply of the Four-Ball Wear Test Machine known to the committee at this time is Falex Corp., 1020 Airpark Dr., Sugar Grove, IL 60554. If you
are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of
the responsible technical committee, which you may attend.
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.
*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
D5183 − 21a
FIG. 1 Schematic of a Four-Ball Wear Test Machine
4. Summary of Test Method
4.1 Three 12.7 mm (0.5 in.) diameter steel balls are clamped together and covered with 10 mL of the wear-in lubricant. A fourth
12.7 mm diameter ball, referred to as the “top ball” is pressed with a force of 392 N (40 kgf) into the cavity formed by the three
clamped balls for three-point contact. The temperature of the wear-in lubricant is regulated at 75 °C (167 °F), and then, the top
ball is rotated at 600 r ⁄min for 60 min.
4.2 Fluid is discarded and balls cleaned. The wear scar diameter on each of the lower three balls is examined. If the wear scars
average 0.67 mm 6 0.03 mm, (0.026 in. 6 0.001 in.) then the 10 mL of test fluid is added to the ball cup with the worn-in test
balls in place. The temperature of the test lubricant is regulated at 75 °C (167 °F) and the top ball is rotated at 600 r ⁄min at 98.1 N
(10 kgf) for 10 min.
4.3 The load is then increased by 98.1 N (10 kgf) at the end of each successive 10 min interval up to the point where the frictional
trace indicates incipient seizure. The coefficient of friction is measured at the end of each 10 min interval.
5. Significance and Use
5.1 This test method can be used to determine the coefficient of friction of lubricating fluids under the prescribed test conditions.
The user of this test method should determine to his own satisfaction whether results of this test method correlate with field
performance or other bench test machines.
6. Apparatus
6.1 Four-Ball Test Machine —See Figs. 1-3.
NOTE 1—It is important to distinguish between the Four-Ball E.P. and the Four-Ball Wear Test Machine (see Test Method D4172). The Four-Ball E.P.
Test Machine is designed for testing under heavier loads and lacks the sensitivity necessary for wear tests.
6.2 Microscope, capable of measuring the diameters of the scars produced on the three balls to an accuracy of 0.01 mm without
removal from the ball test cup.
6.3 Test Balls, chrome alloy steel, made from AISI Standard Steel No. E-52100, with diameter of 12.7 mm (0.5 in.) Grade 25 EP
(extra polish). Such balls are described in ANSI Specifications B3.12.3290-1-2014. The extra-polish finish is not described in that
specification. The Rockwell C hardness shall be 64 to 66, a closer limit than is found in the ANSI requirement.
7. Reagents and Materials
7.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where such
The Four-Ball Wear Test Machine and the Falex Multi-Specimen Friction and Wear Test Machine, both made by Falex Corp., 1020 Airpark Dr., Sugar Grove, IL 60554
have been found satisfactory for this purpose. This company can also furnish a microscope with a special base to measure the wear scars without removing the balls from
the test-oil cup. Discontinued models of the Four-Ball Wear Test Machine made by Precision Scientific Co. and Roxana Machine Works are also satisfactory.
D5183 − 21a
FIG. 2 Falex Variable—Speed Four-Ball Wear Test Machine
specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity
to permit its use without lessening the accuracy of the determination.
7.2 Wear-In Lubricant, white oil having a viscosity at 40 °C of 24.3 cSt to 26.1 cSt (100 °F of 125/135 SUS). It should be
percolated through activated alumina to remove any residual impurities.
7.3 Acetone—(Warning—Flammable. Health hazard.)
7.4 n-Heptane—(Warning—Flammable. Health hazard.)
8. Preparation of Apparatus
8.1 Set up the drive of the machine to obtain a spindle speed of 600 r ⁄min 6 30 r ⁄min.
8.2 Set temperature regulator to produce a test-oil temperature of 75 °C 6 2 °C (167 °F 6 4 °F).
8.3 If an automatic timer is used to terminate a test, it should be checked for the required 61 min accuracy at 60 min elapsed time,
and 610 s at 10 min elapsed time.
8.4 The loading mechanism should be balanced to a zero reading with all parts and test oil in place. To demonstrate proper
precision an addition or subtraction of 2.0 N (0.2 kgf) should be detectable in imbalance. Determination of accuracy of loading at
ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference Materials, American Chemical Society, Washington, DC. For
suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and
the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
D5183 − 21a
FIG. 3 Falex Multi-Specimen Friction and Wear Test Machine
147 N and 392 N (15 kgf and 40 kgf) is difficult and generally limited to careful measurement of lever-arm ratios and weights or
piston diameter and pressure gauge calibration.
NOTE 2—Because of differences in the construction of the various machines on which the four-ball can be made, the manufacturer’s instructions should
be consulted for proper machine set up and operation.
9. Conditioning
9.1 Test Conditions—See Table 1.
10. Procedure
10.1 Thoroughly clean four test balls, clamping parts for upper and lower balls and the ball cup by first soaking in heptane for
1 min and then with sonic agitation for 10 s. Drain and rinse with fresh heptane.
10.1.1 Repeat 10.1 using acetone. Blow dry under a stream of nitrogen gas. After cleaning, handle all parts using only a fresh wipe.
No trace of solvent should remain when wear-in lubricant is introduced and the machine assembled.
10.2 Tighten one of the clean balls into the spindle of the t
...