National foreword

This British Standard is the UK implementation of ISO 1099:2026. It supersedes BS ISO 1099:2017, which is withdrawn.

The UK participation in its preparation was entrusted to Technical Committee ISE/101/6, Fatigue testing of metals and metal matrix composites.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2026.

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO document should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 164, Mechanical testing of metals, Subcommittee SC 4, Fatigue testing.

This fourth edition cancels and replaces the third edition (ISO 1099:2017), which has been technically revised.

The main changes are as follows:

format has been changed to be similar to ISO 22407:2021, ISO 1143:2021 and ISO 1352:2021.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

This document is intended to provide requirements and guidance for conducting axial, constant-amplitude, force-controlled, cyclic fatigue tests on specimens of a metal for the sake of generating fatigue-life data (i.e. stress vs. cycles to failure) for material characterization.

Nominally identical specimens are mounted in an axial force-type fatigue-testing machine and subjected to the required cyclic force conditions that introduce any one of the types of cyclic stress as illustrated in Figure 1. The test waveform should be of constant amplitude and sinusoidal unless otherwise specified.

The force being applied to the specimen is along the longitudinal axis passing through the centroid of each cross-section. The test is continued until the specimen fails or until a predetermined number of stress cycles have been exceeded (see Clauses 4 and 10). Tests are typically conducted at ambient temperature (ideally between 10 °C to 35 °C).

NOTE The results of a fatigue test can be affected by atmospheric conditions and where controlled conditions are required, ISO 554:1976, 2.1 applies.

Caution should be taken regarding the selected test temperature of such isothermal testing so that there are no possible phase changes in the material's microstructure. At elevated temperature creep phenomena can occur. It is recommended to maintain the test temperature, T, at ≤ 0,3 of the melting temperature, T_m, of the material being tested, i.e. the homologous temperature defined as: T_h = T(K)/T_m(K).

1 Scope

This document specifies the conditions for conducting axial, constant-amplitude, force-controlled, fatigue tests at ambient, elevated, and low temperature on metallic specimens, without deliberately introduced stress concentrations. The object of testing while employing this document is to provide fatigue information, such as the relation between applied stress and number of cycles to failure for a given material condition, such as microstructure, at various stress ratios.

While the form, preparation and testing of specimens of circular and rectangular cross-section are described, component testing and other specialized forms of testing are not included in this document.

NOTE 1 Fatigue tests on notched specimens are not covered by this document since the shape and size of notched test pieces have not been standardized. However, fatigue-test procedures described in this document can be applied to fatigue tests of such notched specimens.

NOTE 2 Throughout this document, the engineering stress is employed. Engineering stress is equal to the axially applied force divided by the cross-sectional area of the test specimen, S = Force/Area, [MPa], at the test temperature.

2 Normative references

3 Terms and definitions

4 Test plan

5 Specimen shape and dimensions

5.1 Form of specimens

5.2 Dimension of specimens

6 Preparation of specimens

6.1 General

6.2 Machining procedure

6.3 Sampling and marking

7 Apparatus

7.1 Force transducer

7.2 Test machine

7.3 Alignment check

8 Procedure

8.1 Gripping of specimen

8.2 Mounting of specimen

8.3 Selecting testing frequencies

8.4 Application of force

8.5 Recording of temperature and humidity

9 Heating device and temperature measurement

10 Instrumentation for test monitoring

10.1 Recording systems

10.2 Cycle counter

10.3 Criterion of failure

10.4 Test termination

11 Checking and verification

12 Test report

Bibliography