ASTM E468/E468M-23a

Standard Practice for Presentation of Constant Amplitude Fatigue Test Results for Metallic Materials

SIGNIFICANCE AND USE
4.1 Fatigue test results may be significantly influenced by the properties and history of the parent material, the operations performed during the preparation of the fatigue specimens, and the testing machine and test procedures used during the generation of the data. The presentation of fatigue test results should include citation of basic information on the material, specimens, and testing to increase the utility of the results and to reduce to a minimum the possibility of misinterpretation or improper application of those results.
SCOPE
1.1 This practice covers the desirable and minimum information to be communicated between the originator and the user of data derived from constant-force amplitude axial, bending, or torsion fatigue tests of metallic materials tested in air and at room temperature.  
Note 1: Practice E466, although not directly referenced in the text, is considered important enough to be listed in this standard.  
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
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.  
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-2023
• ICS: 77.040.10 - Mechanical testing of metals
• Technical Committee: E08 - Fatigue and Fracture
• Drafting Committee: E08.05 - Cyclic Deformation and Fatigue Crack Formation

Relations

• Replaces: ASTM E468/E468M-23 - Standard Practice for Presentation of Constant Amplitude Fatigue Test Results for Metallic Materials
• Effective Date: 01-Nov-2023
• Refers: ASTM E1823-24a - Standard Terminology Relating to Fatigue and Fracture Testing
• Effective Date: 15-Feb-2024
• Refers: ASTM E1823-24 - Standard Terminology Relating to Fatigue and Fracture Testing
• Effective Date: 01-Feb-2024
• Refers: ASTM E8/E8M-24 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM E1823-23 - Standard Terminology Relating to Fatigue and Fracture Testing
• Effective Date: 01-Feb-2023
• Refers: ASTM E8/E8M-22 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-May-2022

Overview

ASTM E468/E468M-23a: Standard Practice for Presentation of Constant Amplitude Fatigue Test Results for Metallic Materials provides comprehensive guidelines for documenting and presenting data derived from constant-force amplitude axial, bending, or torsion fatigue tests of metallic materials. This ASTM standard outlines both the minimum and desirable information to be communicated between data originators and users, ensuring clarity and consistency in fatigue test reporting. The standard is developed by ASTM Committee E08 on Fatigue and Fracture, following internationally recognized principles of standardization.

Key Topics

• Minimum Reporting Requirements: Specifies the essential information that must accompany fatigue test results, including detailed material specifications, specimen preparation, and test procedures.
• Material Information: Recommends documenting the grade, form, heat number, melting practice, mechanical and chemical properties, surface condition, and prior mechanical or heat treatments of the tested material.
• Specimen Details: Stresses the need for detailed descriptions of fatigue specimen geometry, preparation, and surface treatments, including notched or unnotched conditions and any post-preparation storage or handling.
• Test Methods: Outlines requirements for documenting the type of test performed (axial, rotary bending, torsion), equipment used, test frequency, force verification and monitoring, and ambient conditions such as temperature and humidity.
• Data Presentation: Provides guidance on presenting fatigue test data clearly in both tabular and graphical formats, such as S-N (stress-life) and constant life diagrams. Describes how to document statistical analysis, regression fitting, and interpretation of fatigue life results.

Applications

ASTM E468/E468M-23a is widely used in research, quality control, and product development where accurate fatigue life characterization of metallic materials is critical. Its applications include:

• Material Selection and Evaluation: Engineers and material scientists use the standard to compare fatigue performance of metals in aerospace, automotive, civil engineering, and industrial applications.
• Quality Assurance: Manufacturers reference this practice when certifying product durability through fatigue testing, supporting compliance and traceability requirements.
• Fatigue Data Sharing: Researchers and laboratories use these guidelines to ensure that fatigue test results are reproducible and interpretable across different organizations, enhancing collaboration.
• Test Program Design: Provides a checklist for planning and executing fatigue tests, including statistical analysis and data reporting, contributing to robust experimental methodologies.

Related Standards

• ASTM E466: Practice for Conducting Force Controlled Constant Amplitude Axial Fatigue Tests of Metallic Materials.
• ASTM E8/E8M: Test Methods for Tension Testing of Metallic Materials.
• ASTM E467: Practice for Verification of Constant Amplitude Dynamic Forces in an Axial Fatigue Testing System.
• ASTM E739: Guide for Statistical Analysis of Linear or Linearized Stress-Life (S-N) and Strain-Life (ε-N) Fatigue Data (withdrawn 2024).
• ASTM E6: Terminology Relating to Methods of Mechanical Testing.
• ASTM E1823: Terminology Relating to Fatigue and Fracture Testing.
• STP 91-A: A Guide for Fatigue Testing and the Statistical Analysis of Fatigue Data.
• STP 588: Manual on Statistical Planning and Analysis.

Practical Value

By standardizing the presentation of constant amplitude fatigue test results, ASTM E468/E468M-23a improves the accuracy, transparency, and utility of fatigue data across industries. It helps organizations achieve better material reliability predictions, supports informed design decisions, and promotes best practices in mechanical testing. Adherence to this standard reduces the risk of data misinterpretation, supports compliance with global testing norms, and ultimately contributes to safer, more reliable engineering outcomes.

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: E468/E468M − 23a
Standard Practice for
Presentation of Constant Amplitude Fatigue Test Results for
Metallic Materials
This standard is issued under the fixed designation E468/E468M; 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 E466 Practice for Conducting Force Controlled Constant
Amplitude Axial Fatigue Tests of Metallic Materials
1.1 This practice covers the desirable and minimum infor-
E467 Practice for Verification of Constant Amplitude Dy-
mation to be communicated between the originator and the user
namic Forces in an Axial Fatigue Testing System
of data derived from constant-force amplitude axial, bending,
E739 Guide for Statistical Analysis of Linear or Linearized
or torsion fatigue tests of metallic materials tested in air and at
Stress-Life (S-N) and Strain-Life (ε-N) Fatigue Data
room temperature.
(Withdrawn 2024)
NOTE 1—Practice E466, although not directly referenced in the text, is
E1823 Terminology Relating to Fatigue and Fracture Testing
considered important enough to be listed in this standard.
2.2 Special Technical Publications:
1.2 The values stated in either SI units or inch-pound units
STP 91–A A Guide for Fatigue Testing and the Statistical
are to be regarded separately as standard. The values stated in
Analysis of Fatigue Data
each system are not necessarily exact equivalents; therefore, to
STP 588 Manual on Statistical Planning and Analysis
ensure conformance with the standard, each system shall be
3. Terminology Definitions and Nomenclature
used independently of the other, and values from the two
systems shall not be combined.
3.1 The terms and abbreviations used in this practice are
1.3 This standard does not purport to address all of the defined in Terminology E6 and in Terminology E1823.
safety concerns, if any, associated with its use. It is the
4. Significance and Use
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4.1 Fatigue test results may be significantly influenced by
mine the applicability of regulatory limitations prior to use.
the properties and history of the parent material, the operations
1.4 This international standard was developed in accor-
performed during the preparation of the fatigue specimens, and
dance with internationally recognized principles on standard-
the testing machine and test procedures used during the
ization established in the Decision on Principles for the
generation of the data. The presentation of fatigue test results
Development of International Standards, Guides and Recom-
should include citation of basic information on the material,
mendations issued by the World Trade Organization Technical
specimens, and testing to increase the utility of the results and
Barriers to Trade (TBT) Committee.
to reduce to a minimum the possibility of misinterpretation or
improper application of those results.
2. Referenced Documents
5. Listing of Basic Information About Fatigue Test
2.1 ASTM Standards:
Specimen
E6 Terminology Relating to Methods of Mechanical Testing
5.1 Specification and Properties of Material:
E8/E8M Test Methods for Tension Testing of Metallic Ma-
5.1.1 Material Prior to Fatigue Test Specimen
terials
Preparation—The minimum information to be presented
should include the designation or specification (for example,
A441, SAE 1070, and so forth) or proprietary grade; form of
This practice is under the jurisdiction of ASTM Committee E08 on Fatigue and
product (for example, plate, bar, casting, and so forth); heat
Fracture and is the direct responsibility of E08.05 E08.05 on Cyclic Deformation
number; melting practice; last mechanical working and last
and Fatigue Crack Formation.
Current edition approved Nov. 1, 2023. Published January 2024. Originally
approved in 1972. Last previous edition approved in 2023 as E468/E468M –23.
DOI: 10.1520/E0468_E0468M-23A. The last approved version of this historical standard is referenced on
For referenced ASTM standards, visit the ASTM website, www.astm.org, or www.astm.org.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM A Guide for Fatigue Testing and the Statistical Analysis of Fatigue Data,
Standards volume information, refer to the standard’s Document Summary page on ASTM International, 1963.
the ASTM website. Manual on Statistical Planning and Analysis, ASTM International, 1975.,
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E468/E468M − 23a
heat treatment that produced the material in the “as-received” 5.3.1.1 It is desirable but not required (unless by mutual
condition (for example, cold-worked and aged, annealed and consent of the originator and user of the data) to include details
rolled, and so forth); chemical composition; and surface of the operations performed (for example, feed, speed, depth of
condition (for example, rolled and descaled, ground, and so cut and coolants, thermal cycles, etc.), and the surface residual
forth). stresses of the specimen, if measured.
5.1.1.1 It is desirable but not required (unless by mutual 5.3.2 Condition of Specimens Prior to Fatigue Testing—It is
consent of the originator and user of the data) to list the raw desirable but not required to list the environment in which the
material production sequence, billet preparation, results of specimens were stored, type of protection applied to the
cleanliness analysis, or a combination thereof, when appli- specimens, and method used to remove that protection. It is
cable. desirable but not required to list the average and range of
surface roughness, surface hardness, out-of-flatness, out-of-
5.1.2 Material in the Fatigue Test Specimen:
straightness or warpage, or a combination thereof, of all fatigue
5.1.2.1 Mechanical Properties—The minimum data on the
specimens.
mechanical properties of the material in a condition identical to
that of the fatigue test specimen should include the tensile
6. Listing of Information on Test Procedures
strength, yield point or yield strength at a specified onset;
elongation in a specified gage length; reduction of area when
6.1 Design of the Fatigue Test Program:
applicable; and the designation of the test used to procure the
6.1.1 If statistical techniques were used to design the fatigue
mechanical properties (for example, Test Methods E8/E8M,
test program, the design plan and list of statistical techniques
Tension Testing of Metallic Materials, and so forth). If notched
(for example, randomization of test sequence, blocking, etc.)
fatigue tests were conducted, the notched tensile strength also
used to accommodate expected or observed heterogeneities
should be listed.
should be presented. Some statistical techniques are described
5.1.2.2 Metallography—It is desirable but not required (un-
in STP 91–A, STP 588, and Guide E739.
less by mutual consent of the originator and user of the data) to
6.2 Fatigue Testing Machine:
list the grain size (when applicable), phases, and dispersions
characteristic of the fatigue test specimen in the “ready-to-test”
6.2.1 Minimum information to be presented shall include
condition. the type of testing machine, the functional characteristic (for
example, servohydraulic, electro-mechanical, etc.), frequency
5.1.2.3 It is desirable but not required (unless by mutual
of force application, and forcing function (for example, sine,
consent of the originator and user of the data) to show the
square, etc.). If tests were performed on more than one
locations, in the parent material, from which the specimens
machine, the number of testing machines used should be listed.
were taken.
6.2.2 Minimum information should include the method of
5.2 Minimum Information to Be Presented on Design of
dynamic force verification and force monitoring procedures.
Fatigue Test Specimen in the “Ready-To-Test” Conditions:
5.2.1 Shape, Size, and Dimensions—A drawing showing NOTE 2—For guidance on axial fatigue testing systems, refer to Practice
E467.
shape, size, and dimensions of the fatigue test specimen should
be presented including details on test section, grip section,
6.3 Fatigue Test:
fillets, radii, swaged portions, holes, and orientation of the
6.3.1 Minimum information to be presented shall include
fatigue test specimen with respect to the direction of maximum
the type of test (axial, rotary bending, plane bending, or
working of the material. When reporting the test results of
torsion), the derivation (or method of computation) of the test
notched fatigue specimens, the geometry of the notch, its
section dynamic stresses, and, when applicable, the experimen-
dimensions and stress concentration factor, the method of
tal stress analysis techniques (for example, electric resistance
derivation of the stress concentration factor, and whether the
strain gages, photoelastic coating, etc.) used. The failure
stress concentration factor is based on the gross or net area of
criterion and number of cycles to run-out used in the test
the test section should be presented.
program shall be presented.
5.3 Listing of Information on Specimen Preparation:
6.3.1.1 It is desirable but not required (unless by mutual
5.3.1 The minimum information to be presented should list, consent of the originator and user of the data) to include the
in chronological order, the operations performed on the fatigue procedure for mounting the specimen in the testing machine,
test specimen, including the type of process used to form the grip details, and precautions taken to ensure that stresses
induced by vibration, friction, eccentricity, etc., were negli-
specimen (for example, milling, turning, grinding, etc.), ther-
mal treatment (for example, stress relieving, aging, etc.), and gible.
surface treatment (for example, shot-peening, nitriding,
6.4 Ambient Conditions During the Fatigue Test—
coating, etc.). If the final specimen surface treatment is
Minimum information to be presented shall include the average
polishing, the polishing seque
...

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: E468/E468M − 23 E468/E468M − 23a
Standard Practice for
Presentation of Constant Amplitude Fatigue Test Results for
Metallic Materials
This standard is issued under the fixed designation E468/E468M; 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 practice covers the desirable and minimum information to be communicated between the originator and the user of data
derived from constant-force amplitude axial, bending, or torsion fatigue tests of metallic materials tested in air and at room
temperature.
NOTE 1—Practice E466, although not directly referenced in the text, is considered important enough to be listed in this standard.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used
independently of the other, and values from the two systems shall not be combined.
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.
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:
E6 Terminology Relating to Methods of Mechanical Testing
E8/E8M Test Methods for Tension Testing of Metallic Materials
E466 Practice for Conducting Force Controlled Constant Amplitude Axial Fatigue Tests of Metallic Materials
E467 Practice for Verification of Constant Amplitude Dynamic Forces in an Axial Fatigue Testing System
E739 Guide for Statistical Analysis of Linear or Linearized Stress-Life (S-N) and Strain-Life (ε-N) Fatigue Data (Withdrawn
2024)
E1823 Terminology Relating to Fatigue and Fracture Testing
This practice is under the jurisdiction of ASTM Committee E08 on Fatigue and Fracture and is the direct responsibility of E08.05 E08.05 on Cyclic Deformation and
Fatigue Crack Formation.
Current edition approved May 15, 2023Nov. 1, 2023. Published June 2023January 2024. Originally approved in 1972. Last previous edition approved in 20182023 as
E468E468/E468M —18. DOI: 10.1520/E0468_E0468M-23. –23. DOI: 10.1520/E0468_E0468M-23A.
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.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E468/E468M − 23a
2.2 Special Technical Publications:
STP 91–A A Guide for Fatigue Testing and the Statistical Analysis of Fatigue Data
STP 588 Manual on Statistical Planning and Analysis
3. Terminology Definitions and Nomenclature
3.1 The terms and abbreviations used in this practice are defined in Terminology E6 and in Terminology E1823.
4. Significance and Use
4.1 Fatigue test results may be significantly influenced by the properties and history of the parent material, the operations
performed during the preparation of the fatigue specimens, and the testing machine and test procedures used during the generation
of the data. The presentation of fatigue test results should include citation of basic information on the material, specimens, and
testing to increase the utility of the results and to reduce to a minimum the possibility of misinterpretation or improper application
of those results.
5. Listing of Basic Information About Fatigue Test Specimen
5.1 Specification and Properties of Material:
5.1.1 Material Prior to Fatigue Test Specimen Preparation—The minimum information to be presented should include the
designation or specification (for example, A441, SAE 1070, and so forth) or proprietary grade; form of product (for example, plate,
bar, casting, and so forth); heat number; melting practice; last mechanical working and last heat treatment that produced the
material in the “as-received” condition (for example, cold-worked and aged, annealed and rolled, and so forth); chemical
composition; and surface condition (for example, rolled and descaled, ground, and so forth).
5.1.1.1 It is desirable but not required (unless by mutual consent of the originator and user of the data) to list the raw material
production sequence, billet preparation, results of cleanliness analysis, or a combination thereof, when applicable.
5.1.2 Material in the Fatigue Test Specimen:
5.1.2.1 Mechanical Properties—The minimum data on the mechanical properties of the material in a condition identical to that
of the fatigue test specimen should include the tensile strength, yield point or yield strength at a specified onset; elongation in a
specified gage length; reduction of area when applicable; and the designation of the test used to procure the mechanical properties
(for example, Test Methods E8/E8M, Tension Testing of Metallic Materials, and so forth). If notched fatigue tests were conducted,
the notched tensile strength also should be listed.
5.1.2.2 Metallography—It is desirable but not required (unless by mutual consent of the originator and user of the data) to list the
grain size (when applicable), phases, and dispersions characteristic of the fatigue test specimen in the “ready-to-test” condition.
5.1.2.3 It is desirable but not required (unless by mutual consent of the originator and user of the data) to show the locations, in
the parent material, from which the specimens were taken.
5.2 Minimum Information to Be Presented on Design of Fatigue Test Specimen in the “Ready-To-Test” Conditions:
5.2.1 Shape, Size, and Dimensions—A drawing showing shape, size, and dimensions of the fatigue test specimen should be
presented including details on test section, grip section, fillets, radii, swaged portions, holes, and orientation of the fatigue test
specimen with respect to the direction of maximum working of the material. When reporting the test results of notched fatigue
specimens, the geometry of the notch, its dimensions and stress concentration factor, the method of derivation of the stress
concentration factor, and whether the stress concentration factor is based on the gross or net area of the test section should be
presented.
5.3 Listing of Information on Specimen Preparation:
A Guide for Fatigue Testing and the Statistical Analysis of Fatigue Data, ASTM International, 1963.
Manual on Statistical Planning and Analysis, ASTM International, 1975.,
E468/E468M − 23a
5.3.1 The minimum information to be presented should list, in chronological order, the operations performed on the fatigue test
specimen, including the type of process used to form the specimen (for example, milling, turning, grinding, etc.), thermal treatment
(for example, stress relieving, aging, etc.), and surface treatment (for example, shot-peening, nitriding, coating, etc.). If the final
specimen surface treatment is polishing, the polishing sequence and direction should be listed. If deterioration of the specimen
surface is observed during storage, after preparation but prior to testing, the procedures that were used to eliminate the defects and
changes, if any, in shape, dimensions, or mechanical properties should be listed.
5.3.1.1 It is desirable but not required (unless by mutual consent of the originator and user of the data) to include details of the
operations performed (for example, feed, speed, depth of cut and coolants, thermal cycles, etc.), and the surface residual stresses
of the specimen, if measured.
5.3.2 Condition of Specimens Prior to Fatigue Testing—It is desirable but not required to list the environment in which the
specimens were stored, type of protection applied to the specimens, and method used to remove that protection. It is desirable but
not required to list the average and range of surface roughness, surface hardness, out-of-flatness, out-of-straightness or warpage,
or a combination thereof, of all fatigue specimens.
6. Listing of Information on Test Procedures
6.1 Design of the Fatigue Test Program:
6.1.1 If statistical techniques were used to design the fatigue test program, the design plan and list of statistical techniques (for
example, randomization of test sequence, blocking, etc.) used to accommodate expected or observed heterogeneities should be
presented. Statistical Some statistical techniques are described in STP 91–A and STP91–A, STP 588, and Guide E739588.
6.2 Fatigue Testing Machine:
6.2.1 Minimum information to be presented shouldshall include the type of testing machine, the functional characteristic (for
example, electrohydraulic,servohydraulic, electro-mechanical, etc.), frequency of force application, and forcing function (for
example, sine, square, etc.). If tests were performed on more than one machine, the number of testing machines used should be
listed.
6.2.2 Minimum information should include the method of dynamic force verification and force monitoring procedures.
NOTE 2—For guidance on axial fatigue testing systems, refer to Practice E467.
6.3 Fatigue Test:
6.3.1 Minimum information to be presented shouldshall include the type of test (axial, rotary bending, plane bending, or torsion),
the derivation (or method of computation) of the test section dynamic stresses, and, when applicable, the experimental stress
analysis techniques (for example, electric resistance strain gages, photoelastic coating, etc.) used. The failure criterion and number
of cycles to run-out used in the test program shall be presented.
6.3.1.1 It is desirable but not required (unless by mutual consent of the originator and user of the data) to include the procedure
for mounting the specimen in the testing machine, grip details, and precautions taken to ensure that stresses induced by vibration,
friction, eccentricity, etc., were negligible.
6.4 Ambient Conditions During the Fatigue Test—Minimum info
...