National foreword

This British Standard is the UK implementation of ISO 13284:2026. It supersedes BS ISO 13284:2022, which is withdrawn.

The UK participation in its preparation was entrusted to Technical Committee MHE/7, Industrial trucks.

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 May 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 110, Industrial trucks, Subcommittee SC 2, Safety of powered industrial trucks.

This third edition cancels and replaces the second edition (ISO 13284:2022), which has been technically revised.

The main changes are as follows:

the lateral clearance for fork extensions has been changed to include upper and lower limits.

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 was developed in response to worldwide demand for specifications for fork arm extensions and telescopic fork arms.

Fork arm extensions are used as a temporary means of extending the effective blade length of fork arms on industrial trucks. They are available with either a closed rectangular cross-section or an open inverted-channel cross-section.

Whenever possible, longer forks should be used instead of fork arm extensions.

Telescopic fork arms replace standard fork arms and provide the truck operator with the means of adjusting the fork arm blade length. They are available either as simple variable-length fork arms for handling loads of varying dimensions or for reaching out or retracting palletized loads in double-deep stacking and de-stacking operations.

1 Scope

This document specifies technical characteristics and strength requirements for fork arm extensions and telescopic fork arms (as defined in ISO 5053‑2) for industrial trucks (as defined in ISO 5053‑1). It applies to fork arm extensions and telescopic fork arms that are designed for use on industrial trucks that have fork arm carriers and, in the case of fork arm extensions, fork arms that conform to ISO 2330.

This document does not apply to integral transverse telescopic fork devices or scissor-action reach devices.

2 Normative references

3 Terms and definitions

4 Symbols

5 Requirements for rated capacity and rated load centre distance

5.1 Fork arm

5.2 Fork arm extension

5.3 Telescopic fork arm

5.4 Safety factor

6 Requirements for fork arm extensions

6.1 Length

6.2 Accidental disengagement

6.3 Test/design load

6.4 Fork arm extension retaining system

6.5 Lateral clearance

7 Requirements for telescopic fork arms

7.1 General

7.2 Test load in fully retracted mode with pallet stop

7.3 Test load in fully retracted mode without pallet stop

7.4 Test load in fully extended mode with pallet stop

7.5 Test load in fully extended mode without pallet stop

8 Verification and testing

8.1 General

8.2 Procedure

8.3 Results

9 Information for use

9.1 Fork arm extensions

9.2 Telescopic fork arms

10 Marking

10.1 Fork arm extensions

10.2 Telescopic fork arms

Bibliography

BS ISO 13284:2026

Industrial trucks. Fork arm extensions and telescopic fork arms. Technical characteristics and strength requirements

Current

Published:

31 May 2026