ASTM G223-23

Standard Test Method for Measuring Friction and Adhesive Wear Properties of Lubricated and Nonlubricated Materials Using the Twist Compression Test (TCT)

SIGNIFICANCE AND USE
5.1 This test method is designed to rank material couples, surface treatments, and lubricants by CFT and in their resistance to adhesive wear. Since adhesive wear is a complex phenomenon and stochastic in nature, it is essential to evaluate surfaces to confirm the presence of adhesion.  
5.2 This test method should be considered when evaluating the impact of changes in a process or application that is prone to adhesive wear, including any combination of scoring, galling, and plowing. These modes of failure commonly occur under sliding contact, at high contact stress, and, when applicable, at lubricant starvation.  
5.3 The TCT is often used to evaluate the ability of material couples, surface treatments, coatings, and lubricants to prevent or reduce adhesive wear in metalworking operations including deep drawing, extrusion, and pipe bending. Other applications in which the test may be effective are loader bucket bushings, gear teeth at startup, and low-clearance pumps.  
5.4 This test method is best used as a comparative screening tool. The ranking of performance produced by the TCT correlates well with the ranking in many applications.3 However, since the test is a bench test and not directly reproducing any specific application, TCT results should be only used as an indicator of the tendency for adhesive wear to occur. TCT is a useful screening test for comparing the effectiveness of material couples, surface treatments, coatings, and lubricant formulations before process testing and field trials.
SCOPE
1.1 This test method covers laboratory procedures for determining the coefficient of friction (COF) and resistance of materials to adhesion under flat sliding using the twist compression test (TCT). This test method ranks material couples, surface treatments, coatings, and lubricant combinations by COF and their resistance to adhesion.  
1.2 The time until adhesion for the materials under the test conditions are reported and used to quantify the tribocouple’s adhesion resistance and susceptibility to galling or scuffing. Systems of higher adhesion resistance will give longer time until failure.  
1.3 The coefficient of friction values averaged between the test reaching full test pressure and the time of the onset of adhesion or the end of tests run for a predetermined time period are recorded. Systems are ranked by their average coefficients of friction before adhesion occurs.  
1.4 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard except psi and pounds in Table 1.  
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: 31-May-2023
• ICS: 17.040.20 - Properties of surfaces
• ICS: 77.060 - Corrosion of metals
• Technical Committee: G02 - Wear and Erosion
• Drafting Committee: G02.40 - Non-Abrasive Wear

Relations

• Refers: ASTM G40-15 - Standard Terminology Relating to Wear and Erosion
• Effective Date: 01-Nov-2015
• Refers: ASTM G40-13 - Standard Terminology Relating to Wear and Erosion
• Effective Date: 01-Jun-2013
• Refers: ASTM G40-12 - Standard Terminology Relating to Wear and Erosion
• Effective Date: 01-May-2012
• Refers: ASTM G40-10b - Standard Terminology Relating to Wear and Erosion
• Effective Date: 01-Dec-2010
• Refers: ASTM G40-10a - Standard Terminology Relating to Wear and Erosion
• Effective Date: 01-Jul-2010
• Refers: ASTM G40-10 - Standard Terminology Relating to Wear and Erosion
• Effective Date: 01-Jan-2010
• Refers: ASTM G40-09 - Standard Terminology Relating to Wear and Erosion
• Effective Date: 15-Nov-2009
• Refers: ASTM G40-05 - Standard Terminology Relating to Wear and Erosion
• Effective Date: 01-May-2005
• Refers: ASTM G40-04 - Standard Terminology Relating to Wear and Erosion
• Effective Date: 01-Dec-2004
• Refers: ASTM G40-02 - Standard Terminology Relating to Wear and Erosion
• Effective Date: 10-Oct-2002
• Refers: ASTM G40-01 - Standard Terminology Relating to Wear and Erosion
• Effective Date: 10-Jun-2001
• Refers: ASTM G40-99 - Standard Terminology Relating to Wear and Erosion
• Effective Date: 10-Jun-2001

Overview

ASTM G223-23: Standard Test Method for Measuring Friction and Adhesive Wear Properties of Lubricated and Nonlubricated Materials Using the Twist Compression Test (TCT) provides a laboratory-based procedure for ranking materials, surface treatments, and lubricants by their coefficient of friction (COF) and resistance to adhesive wear. This international standard is designed to support industries where sliding contact, high-stress environments, and wear-induced failures such as galling and scoring are significant concerns. The method is suitable for both lubricated and nonlubricated systems, offering an effective comparative screening tool for materials selection and process optimization.

Key Topics

• Coefficient of Friction (COF): The test determines the average COF in flat-on-flat sliding contact, comparing material pairs, surface treatments, and lubricant combinations under controlled laboratory conditions.
• Adhesive Wear: The TCT identifies adhesive wear phenomena, such as galling, plowing, and scoring, through measurement of adhesion onset and inspection of tested surfaces.
• Test Procedure: The method describes using a twist compression apparatus, applying consistent pressure and rotational speed to specimens of defined geometry, and measuring transmitted torque and normal force.
• Material and Surface Evaluation: Both the time until adhesion begins and the average COF prior to adhesion are recorded, helping to rank tribological performance relevant to application requirements.
• Screening and Comparison: Results are used to compare and rank the performance of material couples, coatings, surface treatments, and lubricants before advancing to more extensive process or field testing.

Applications

The ASTM G223-23 method is especially valuable in various industrial sectors that require reliable assessment of material wear and friction properties:

• Metalworking Operations: Deep drawing, extrusion, and pipe bending processes benefit from materials and lubricants ranked using the TCT, supporting decisions that reduce adhesive wear and extend die/tool life.
• Mechanical Assemblies: Components subject to high sliding stresses-such as loader bucket bushings, gear teeth at startup, and low-clearance pumps-can be evaluated for galling and seizure risks.
• Manufacturing Process Development: TCT serves as an initial screening step to assess new material combinations, surface engineering processes, or lubricant formulations before conducting full-scale or field trials.
• Quality and Process Control: Routine use of the standard helps monitor and optimize changes in manufacturing processes that may influence frictional or wear performance.
• R&D in Tribology: Research and development teams employ TCT results to accelerate innovation in surface treatments and lubricants aimed at minimizing adhesive wear.

Related Standards

Organizations and technical professionals implementing ASTM G223-23 may also reference related standards to enhance tribological testing and material selection:

• ASTM G40 – Terminology Relating to Wear and Erosion, providing definitions for key concepts such as adhesive wear, galling, plowing, and scoring.
• ASTM G99 – Standard Test Method for Wear Testing with a Pin-on-Disk Apparatus, for different sliding wear assessment methods.
• ASTM G133 – Standard Test Method for Linearly Reciprocating Ball-on-Flat Sliding Wear, focusing on sliding wear under reciprocating motion.
• ISO 20808 – Fine Ceramics Determination of Friction and Wear Characteristics of Monolithic Ceramics, providing additional context for ceramic materials.

By following the procedures outlined in ASTM G223-23, industries and research institutions can systematically evaluate and compare the friction and adhesive wear properties of lubricated and nonlubricated materials, enabling informed decisions to prevent premature failure and optimize component longevity in demanding applications.

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: G223 − 23
Standard Test Method for
Measuring Friction and Adhesive Wear Properties of
Lubricated and Nonlubricated Materials Using the Twist
Compression Test (TCT)
This standard is issued under the fixed designation G223; 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 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method covers laboratory procedures for de-
G40 Terminology Relating to Wear and Erosion
termining the coefficient of friction (COF) and resistance of
materials to adhesion under flat sliding using the twist com-
3. Terminology
pression test (TCT). This test method ranks material couples,
3.1 Definitions—Definitions used in this test method are in
surface treatments, coatings, and lubricant combinations by
Terminology G40.
COF and their resistance to adhesion.
3.1.1 adhesive wear, n—wear caused by localized bonding
between contacting solid surfaces leading to material transfer
1.2 The time until adhesion for the materials under the test
between the two surfaces or loss from either surface.
conditions are reported and used to quantify the tribocouple’s
adhesion resistance and susceptibility to galling or scuffing.
3.1.2 apparent area of contact, n—in tribology, the area of
Systems of higher adhesion resistance will give longer time contact between two solid surfaces defined by the boundaries
until failure. of their macroscopic interface.
3.1.3 galling, n—form of surface damage arising between
1.3 The coefficient of friction values averaged between the
sliding solids distinguished by macroscopic, usually localized,
test reaching full test pressure and the time of the onset of
roughening and the creation of protrusions above the original
adhesion or the end of tests run for a predetermined time period
surface; it is characterized by plastic flow and may involve
are recorded. Systems are ranked by their average coefficients
material transfer.
of friction before adhesion occurs.
-2
3.1.4 nominal contact pressure, FL , n—in tribology, an
1.4 Units—The values stated in SI units are to be regarded
average contact pressure between two conforming bodies
as the standard. No other units of measurement are included in
calculated by dividing the contact force by the apparent area of
this standard except psi and pounds in Table 1.
contact.
3.1.5 plowing, n—in tribology, the formation of grooves by
1.5 This standard does not purport to address all of the
plastic deformation of the softer of two surfaces in relative
safety concerns, if any, associated with its use. It is the
motion.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- 3.1.6 scoring, n—in tribology, a severe form of wear char-
acterized by the formation of extensive grooves and scratches
mine the applicability of regulatory limitations prior to use.
in the direction of sliding.
1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard- 3.1.7 scratching, n—in tribology, the mechanical removal or
ization established in the Decision on Principles for the displacement or both of material from a surface by the action
of abrasive particles or protuberances sliding across the sur-
Development of International Standards, Guides and Recom-
faces.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
3.1.8 scuffıng, n—form of adhesive wear occurring in inad-
equately lubricated tribosystems that is characterized by mac-
roscopically observable localized changes in surface texture.
This test method is under the jurisdiction of ASTM Committee G02 on Wear
and Erosion and is the direct responsibility of Subcommittee G02.40 on Non- For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Abrasive Wear. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Current edition approved June 1, 2023. Published July 2023. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
G0223-23. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G223 − 23
3.1.9 sliding wear, n—in tribology, wear caused by the
relative motion in the tangential plane of contact between two
solid bodies.
3.1.10 stick-slip, n—in tribology, a cyclic fluctuation in the
magnitudes of friction force and relative velocity between two
elements in sliding contact, usually associated with a relaxation
oscillation dependent on elasticity in the tribosystem and a
decrease of the coefficient of friction (COF) with onset of
sliding or increase in sliding velocity.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 coeffıcient of friction in twist compression testing,
CFT, n—in twist compression testing (TCT), the transmitted
torsional force at a specific radius of gyration divided by the
applied normal force:
FIG. 1 Radius of Gyration of an Annulus
CFT~dimensionless! 5 F ⁄F (1)
torq, Rg5_ n
where: in both the magnitude of the CFT and in the duration of CFT
versus time graph features.
F = transmitted torsional force at radius and
torq, Rg=_
R and F = normal force.
g n
4.3 The test often ends with the seizure (or cold welding) of
the surfaces. This seizure is often characterized by a rapid rise
3.2.2 radius of gyration, n—in TCT using an annular
contact between a flat specimen and a cylindrical specimen of in torque and the CFT versus time curve. Either the annular
cylinder or the flat surface may be visually examined to
inner radius, R , and outer radius, R , the radius of gyration,
i o
Rg, is defined as: confirm the occurrence of adhesive wear (Fig. 2).
2 2 5. Significance and Use
R 5 =R 1R (2)
g i o
5.1 This test method is designed to rank material couples,
This may be approximated by the mean radius defined as:
surface treatments, and lubricants by CFT and in their resis-
tance to adhesive wear. Since adhesive wear is a complex
R 2 R
~ !
o i
R 5 (3)
mean
phenomenon and stochastic in nature, it is essential to evaluate
surfaces to confirm the presence of adhesion.
3.2.3 seizure, n—localized fusion of metal between the
rubbing surfaces of the test pieces that is characterized by a 5.2 This test method should be considered when evaluating
rapid rise in the CFT versus time curve. the impact of changes in a process or application that is prone
to adhesive wear, including any combination of scoring,
4. Summary of Test Method
galling, and plowing. These modes of failure commonly occur
under sliding contact, at high contact stress, and, when
4.1 The TCT is used to determine the coefficient of friction
applicable, at lubricant starvation.
in twist compression testing, CFT, and adhesion resistance of
nonlubricated and lubricated material couples in conformal 5.3 The TCT is often used to evaluate the ability of material
normal area contacts under continuous unidirectional sliding
couples, surface treatments, coatings, and lubricants to prevent
conditions. While it is most often used to evaluate material or reduce adhesive wear in metalworking operations including
couples, surface treatments, coatings, and lubricants for met-
alworking processes, the TCT has application in other confor-
mal sliding contacts.
4.2 This test method uses laboratory equipment capable of
maintaining a constant, compressive load in a cylindrical
flat-on-flat geometry and a mechanism that will produce the
necessary relative motion between a rotating ring and the fixed
flat specimen. The transmitted torsional force is measured
between the rotating ring and a flat specimen. The coefficient of
friction determined using TCT is referred to as the coefficient
of friction in twist compression testing (CFT). The coefficient
of friction in twist compression testing is the ratio of the
torsional force transmitted from the rotating specimen to the
fixed specimen to the applied normal force. The resulting
contact area is an annulus with approximately the same macro
dimensions as the cylinder end (see Fig. 1). As surface films are
removed or, in the case of lubricated tests, the lubricant is
depleted, the adhesive nature of the contact surfaces is revealed FIG. 2 TCT Specimens after Testing
G223 − 23
deep drawing, extrusion, and pipe bending. Other applications provided it is first ascertained that the reagent is of sufficiently
in which the test may be effective are loader bucket bushings, high purity to permit its use without lessening the accuracy of
gear teeth at startup, and low-clearance pumps. the determination.
5.4 This test method is best used as a comparative screening 7.2 Cleaning Fluids—Test specimens should be cleaned
tool. The ranking of performance produced by the TCT using fluids capable of removing metal preservative coatings
correlates well with the ranking in many applications. that may be present. The cleaning fluid selected should be
However, since the test is a bench test and not directly non-film-forming and not contribute to the friction, load
reproducing any specific application, TCT results should be carrying or antiwear properties of the test couple (for example,
only used as an indicator of the tendency for adhesive wear to chlorinated solvents should not be used).
occur. TCT is a useful screening test for comparing the
7.3 Heptane, laboratory grade.
effectiveness of material couples, surface treatments, coatings,
7.4 Lint-Free Laboratory Tissues.
and lubricant formulations before process testing and field
trials.
8. Test Specimens
8.1 A schematic of the test configuration is shown in Fig. 3.
6. Apparatus
8.1.1 Annular Specimen—The annular specimen is made
6.1 The test should be conducted in an instrument suffi-
from the material of one contacting surface (usually chosen for
ciently rigid to minimize elastic deflection under the high loads
convenience of fabrication). Specimens can be fabricated on a
often used for the test. The test instrument should be capable of
lathe to produce an annulus with a 25.0 mm 6 0.5 mm OD and
providing constant rotational speed, under varying torque,
a 19.0 mm 6 0.5 mm inside diameter at a 90° angle to the
between approximately 5 r ⁄min to 33 r ⁄min for a 25 mm
longitudinal axis of the cylinder (see Fig. 3). When evaluating
outside diameter (OD) hollow cylindrical specimen with a
soft material surfaces such as copper, aluminum, or zinc alloys,
3 mm wall thickness (for reference: 0.006 m ⁄s to 0.040 m ⁄s
sharp edges on the cylindrical specimen contact edges may be
linear speed at radius of gyration). Tests should be carried out
beveled to <0.25 mm radius to reduce edge effects (chamfered
at 10 r ⁄min or 0.012 m ⁄s but may be carried out at other speeds.
or fillet). The annular specimens shall include a means of being
Tests are normally carried out between 7 MPa to 220 MPa
held in the rotating fixture preventing them from turning,
nominal contact pressures. The apparatus shall be capable of
relative to the fixture, under torques during the test. The
applying the appropriate pressure with minimum deformation
annular specimens are treated as they would be for the
of the frame. Tests are normally carried out under ambient
application of interest. The annular surface should be flat and
temperature and humidity conditions. Force transducers mea-
free from visible scratches. Edges should be protected during
sure the normal force and torque transmitted from the rotating
handling to prevent chipping, and specimens with chipped
specimen through the surface contact to the fixed specimen.
contact edges should not be used in tests.
Optionally, other responses such as acoustic emission, electri-
8.1.2 Flat Specimen—The flat specimen is made from the
cal resistance, and temperature may be recorded.
material of the second surface. The flat specimens are also
6.2 Alignment of the Specimens:
treated as they would be in the application of interest. The
6.2.1 Concentric alignment of the hollow cylinder with the
dimensions of the contacting surface shall be large enough to
pivot point of the flat specimen or flat specimen holder shall be
accommodate the 25 mm diameter annulus without interfering
maintained for a concentric contact path.
with debris or lubricant escaping the contact. Flat specimens
6.2.2 Horizontal planar alignment of the contact surfaces of
not thick enough to prevent bending should be supported in a
the specimens shall be maintained.
rigid flat holder. Sheet metal specimens can be cut to fit into a
rigid sheet holder. These specimens shall be flat across the
NOTE 1—TCT designs that use ball bearings for alignment shall be
entire surface of the specimen. Visual examination of the
checked regularly for flat spots.
specimens after a test will confirm flatness of specimens and
7. Reagents and Materials
that uniform contact was made. If the visual examination
indicates significant issues with the contact, then the result
7.1 Purity of Reagents—Reagent-grade chemicals shall be
should be discarded and repeated.
used in all tests. Unless otherwise indicated, it is intended that
8.1.3 Surface Finish—The surfaces should be representative
all reagents conform to the specifications of the Committee on
of the application of interest. An isotropic surface finish
Analytical Reagents of the American Chemical Society where
(lapped) is preferred for the annular specimen contact surface.
such specifications are
...