ISO 7176-32:2022

INTERNATIONAL ISO
STANDARD 7176-32
First edition
2022-05
Wheelchairs —
Part 32:
Test method for wheelchair castor
assembly durability
Fauteuils roulants —
Partie 32: Méthode d'essai pour la durabilité des roues pivotantes des
fauteuils roulants
Reference number
ISO 7176-32:2022(E)
© ISO 2022

---------------------- Page: 1 ----------------------
ISO 7176-32:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
  © ISO 2022 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 7176-32:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Castor assembly classification .2
5 Strength requirements . 2
6 Test apparatus .2
6.1 Corrosion testing machine . 2
6.2 Fatigue testing machine . 3
6.2.1 Testing machine description. 3
6.2.2 Abrasion surface . 3
6.2.3 Obstacle profile . 3
6.2.4 Obstacle placement . 3
6.2.5 Castor assembly loading . 4
7 Test preparation . 4
7.1 Preparation of the castor stem assembly holder and support arm . 4
7.2 Setup of the turntable . 4
7.3 Abrasion surface . 4
7.4 Environmental conditions . 4
7.5 Castor assembly loading conditions . 5
8 Test procedure .7
8.1 Test sequence . 7
8.2 Fatigue and abrasion test procedure . 7
8.3 Corrosion test procedure . 7
8.4 Evaluation of test results. 7
9 Disclosure requirements .8
10 Test report . 8
Annex A (informative) Castor assembly testing system example . 9
Annex B (informative) Castor assembly testing report .11
Bibliography .12
iii
© ISO 2022 – All rights reserved

---------------------- Page: 3 ----------------------
ISO 7176-32:2022(E)
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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
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 173, Assistive products, Subcommittee SC
1, Wheelchairs.
A list of all parts in the ISO 7176 series can be found on the ISO website.
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.
iv
  © ISO 2022 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 7176-32:2022(E)
Introduction
This document has been developed to address the need for evaluation of wheelchair castor assembly
quality. Wheelchair castor assemblies come in different sizes and designs. Most castor assembly designs
are known to fail within three months to two years of use due to impacts, fatigue, and wear caused
[3]
by adverse outdoor conditions . Castor assembly quality issues have been identified. Only a subset of

field castor assembly failures is covered in the ISO 7176-8, which include static, impact and fatigue tests
[2]
. Failures caused by environmental factors (corrosion, dust, dirt, abrasion on rough surfaces) and
heavy impacts while travelling on rocky terrains and transporting wheelchairs are not represented.
To reproduce accurately field failures and to predict castor assembly quality in the laboratory, it is
recommended to conduct castor assembly testing based on outdoor environmental and use conditions.
This document introduces a new wheelchair castor assembly durability testing standard that is
developed based on field evidence.
v
© ISO 2022 – All rights reserved

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 7176-32:2022(E)
Wheelchairs —
Part 32:
Test method for wheelchair castor assembly durability
1 Scope
This document specifies strength requirements and test methods for wheelchair castor assemblies.
The test methods include corrosion, abrasion and fatigue conditions. This document also specifies
requirements for disclosure of test results.
It is applicable to castor assemblies of or developed for use in occupant and to assistant-propelled
manual wheelchairs and electrically powered wheelchairs.
The test requirements are also applicable to wheelchair castor assemblies not necessarily associated or
supplied with a wheelchair.
Castor assemblies including those with anti-tip castor wheels that do not touch the ground during
wheelchair travel are outside the scope of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 7176-11, Wheelchairs — Part 11: Test dummies
ISO 7176-22, Wheelchairs — Part 22: Set-up procedures
ISO 7176-26, Wheelchairs — Part 26: Vocabulary
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
ISO 22877, Castors and wheels — Vocabulary, symbols and multilingual terminology
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7176-26, ISO 22877 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
castor assembly test load
weight supported by the castor
1
© ISO 2022 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 7176-32:2022(E)
3.2
tyre failure
separation of a tyre from the castor wheel or castor wheel axle (in case, the tyre is mounted directly on
the axle) or rupture of the inner tube of a pneumatic tyre, where any of these conditions can lead to a
loss of function
3.3
castor stem assembly
components in a castor stem housing, which includes the casto
...