ISO 16650:2025

International
Standard
ISO 16650
Second edition
Bead wire
2025-08
Fil d'acier pour tringle
Reference number
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
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Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Classification . 2
5 Designation and ordering . 2
5.1 Designation .2
5.2 Information to be supplied by the purchaser.2
6 Requirements . 3
6.1 Chemical composition of steel .3
6.2 Metallic coating .3
6.3 Cumar weight .3
6.4 Mechanical properties .3
6.4.1 General .3
6.4.2 Tensile test results .3
6.4.3 Torsion test .5
6.5 Surface quality .5
6.5.1 General .5
6.5.2 Coating thickness .5
6.6 Delivery conditions . .5
6.6.1 Unit package .5
6.6.2 Welds . .5
6.6.3 Wire straightness .6
6.6.4 Residual torsion .6
6.7 Dimensions and tolerances . .6
6.7.1 Size tolerances .6
6.7.2 Requirements for adhesion .6
7 Testing and inspection . 6
7.1 Tests and inspection documents .6
7.2 Programme for specific inspection .6
7.3 Test procedures .6
7.3.1 Chemical composition .6
7.3.2 Tensile test .7
7.3.3 Torsion test .7
7.3.4 Diameter and out-of-roundness .7
7.3.5 Straightness .7
7.3.6 Residual torsions .7
7.3.7 Adhesion test .7
7.4 Retests .7
8 Marking, labelling, packaging and shelf life . 7
Annex A (informative) Adhesion testing . 9
Annex B (informative) Pulling out test clamp .12
Annex C (informative) Spool .13
Bibliography .15

iii
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 17, Steel, Subcommittee SC 17, Steel wire rod
and wire products.
This second edition cancels and replaces the first edition (ISO 16650:2004), which has been technically
revised.
The main changes are as follows:
— the terms and definitions clause (Clause 3) has been revised;
— super tensile strength has been added in Clause 4;
— the table of chemical composition (former Table 1) of steel has been deleted and subsequent tables have
been renumbered;
— metallic coating (6.2) has been revised;
— cumar weight (6.3) has been added;
— the mechanical properties (6.4) has been revised;
— surface quality (6.5) has been revised;
— delivery conditions (6.6) has been revised;
— torsion test (6.4.3) has been revised;
— adhesion testing (Annex A) has been revised.
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
International Standard ISO 16650:2025(en)
Bead wire
1 Scope
This document specifies the requirements and characteristics of round and flat wire used for strengthening
the bead of all kinds of tyres.
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 404, Steel and steel products — General technical delivery requirements
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 7800, Metallic materials — Wire — Simple torsion test
ISO 10474, Steel and steel products — Inspection documents
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
nominal diameter
d
diameter by which the wire is designated and specified by the purchaser
Note 1 to en
...