IEC 60851-1:2021

Winding wires - Test methods - Part 1: General

IEC 60851-1:2021 specifies the general notes on methods of test for winding wires. It also gives the definitions for terms used in IEC 60851 (all parts). A survey of the contents of IEC 60851-2 to IEC 60851-6 is given in Annex A. This third edition cancels and replaces the second edition published in 1996, and its amendment 1:2003 and amendment 2:2009. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- revision to Clause 2 to update the list of normative references;
- revision to 3.2 atmospheric conditions for testing;
- addition to 3.2 with remarks concerning frequency and management of tests;
- revision to Annex A to update the contents list of IEC 60851 series of tests.

Fils de bobinage - Méthodes d'essai - Partie 1: Généralités

IEC 60851-1:2021 indique les généralités sur les méthodes d'essai des fils de bobinage. Elle fournit également les définitions des termes utilisés dans l’IEC 60851 (toutes les parties). Un aperçu des sommaires de l'IEC 60851-2 à l'IEC 60851-6 figure à l'Annexe A. Cette troisième édition annule et remplace la deuxième édition parue en 1996, son amendement 1:2003 et son amendement 2:2009, et constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente :
- révision de l’Article 2 en vue de mettre à jour la liste des références normatives;
- révision du 3.2 conditions atmosphériques d’essais;
- ajout au 3.2 de remarques portant sur la fréquence et la gestion des essais;
- révision de l'Annexe A destinée à mettre à jour la liste du contenu de la série d’essais IEC 60851.

General Information

• Status: Published
• Publication Date: 05-Jan-2025
• ICS: 29.060.10 - Wires
• Technical Committee: TC 55 - Winding wires
• Drafting Committee: WG 1 - TC 55/WG 1
• Current Stage: PPUB - Publication issued
• Start Date: 16-Jun-2021
• Completion Date: 02-Jul-2021

Relations

• Amended By: IEC 60851-1:2021/AMD1:2025 - Amendment 1 - Winding wires - Test methods - Part 1: General
• Effective Date: 26-Apr-2024
• Revises: IEC 60851-1:1996/AMD1:2003 - Amendment 1 - Winding wires - Test methods - Part 1: General
• Effective Date: 05-Sep-2023
• Revises: IEC 60851-1:1996 - Methods of test for winding wires - Part 1: General
• Effective Date: 05-Sep-2023
• Revises: IEC 60851-1:1996/AMD2:2009 - Amendment 2 - Winding wires - Test methods - Part 1: General
• Effective Date: 05-Sep-2023

Overview

IEC 60851-1:2021 (consolidated with Amendment 1, 2025) - Part 1: General - is the foundational document of the IEC 60851 series on winding wires – test methods. It specifies general notes on methods of test for winding wires, provides the standardized terms and definitions used across the IEC 60851 series, and gives a survey of the test content covered in IEC 60851-2 to IEC 60851-6 (Annex A). This third edition updates normative references, clarifies atmospheric conditions for testing, and adds guidance on test frequency and test management.

Key Topics and Requirements

• Scope and purpose: Defines the general framework for winding wire testing and standardizes terminology for all subsequent parts of IEC 60851.
• Terms & definitions: Authoritative definitions for key concepts such as bonding layer, bunched wire, class, coating, conductor, enamelled wire, insulation, grade, and zero‑defect wire - essential for consistent winding wire testing and specification.
• General test conditions:
  • Standard atmospheric conditions for tests: 15 °C to 40 °C and 25 % to 75 % relative humidity.
  • Specimens must be preconditioned to reach stability before measurements.
  • Handling guidance: remove wire from packaging without introducing tension or bends and discard damaged end lengths before testing.
• Test management:
  • Periodic conformance tests (marked with an asterisk in Annex A) are performed at frequencies agreed between supplier and end user.
  • IEC standards do not prescribe certification management (routine vs non‑routine tests); these are contractual or national matters.
• Traceability & references:
  • Test numbering in IEC 60851 parts corresponds to clause numbers in the IEC 60317 specification sheets.
  • In case of inconsistency, the IEC 60317 specification sheet takes precedence.

Practical Applications and Users

IEC 60851-1 is used by:

• Manufacturers of insulated winding wires for establishing test procedures and quality control.
• Component and equipment designers (motors, transformers, inductors) specifying wire properties for reliable performance.
• Independent test laboratories and QA teams implementing standard test environments and specimen handling.
• Procurement and compliance teams negotiating conformance test frequency and supplier-customer test management. Note: certification bodies and national authorities may impose additional rules for test management beyond this standard.

Related Standards

• IEC 60851 series (Parts 2–6): detailed tests for dimensions, mechanical, chemical, electrical and thermal properties.
• IEC 60317 series: specification sheets for particular types of winding wires (takes precedence where applicable).
• IEC 60264 series: packaging of winding wires.
• IEC Electropedia and ISO/IEC directives for terminology and standardization practices.

Keywords: IEC 60851-1, winding wires, test methods, winding wire testing, insulated wires, IEC 60851 series, IEC 60317.

Standards Content (Sample)

IEC 60851-1 ®
Edition 3.1 2025-01
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
Winding wires – Test methods –
Part 1: General
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Secretariat Tel.: [phone]
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Switzerland
About the IEC
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International Standards for all electrical, electronic and related technologies.

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IEC 60851-1 ®
Edition 3.1 2025-01
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
Winding wires – Test methods –
Part 1: General
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.060.10 ISBN 978-2-8327-0128-7
REDLINE VERSION – 2 – IEC 60851-1:2021+AMD1:2025 CSV
© IEC 2025
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and general notes on methods of test . 6
3.1 Terms and definitions . 6
3.2 General notes on methods of test . 8
Annex A (informative) Contents of IEC 60851-2 to IEC 60851-6 with indication of tests .
A.1 General .
A.2 IEC 60851-2 .
A.3 IEC 60851-3 .
A.4 IEC 60851-4 .
A.5 IEC 60851-5 .
A.6 IEC 60851-6 .
Bibliography . 15

© IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
WINDING WIRES – TEST METHODS –

Part 1: General
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
This consolidated version of the official IEC Standard and its amendment has been
prepared for user convenience.
IEC 60851-1 edition 3.1 contains the third edition (2021-06) [documents 55/1913/FDIS and
55/1916/RVD] and its amendment 1 (2025-01) [documents 55/2057/FDIS and 55/2059/RVD].
In this Redline version, a vertical line in the margin shows where the technical content is
modified by amendment 1. Additions are in green text, deletions are in strikethrough red
text. A separate Final version with all changes accepted is available in this publication.

REDLINE VERSION – 4 – IEC 60851-1:2021+AMD1:2025 CSV
© IEC 2025
IEC 60851-1 has been prepared by IEC technical committee 55: Winding wires. It is an
International Standard.
This third edition cancels and replaces the second edition published in 1996, and its
amendment 1:2003 and amendment 2:2009. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) revision to Clause 2 to update the list of normative references;
b) revision to 3.2 atmospheric conditions for testing;
c) addition to 3.2 with remarks concerning frequency and management of tests;.
d) revision to Annex A to update the contents list of IEC 60851 series of tests.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
Annex A is for information only.
A list of all parts in the IEC 60851 series, published under the general title Winding wires – Test
methods, can be found on the IEC website.
The committee has decided that the contents of this document and its amendment will remain
unchanged until the stability date indicated on the IEC website under webstore.iec.ch in the
data related to the specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

© IEC 2025
INTRODUCTION
This Part of IEC 60851 forms an element of a series of standards which deals with insulated
wires used for windings in electrical equipment. It is composed of the following series:
1) Winding wires – Test methods (IEC 60851 series);
2) Specifications for particular types of winding wires (IEC 60317 series);
3) Packaging of winding wires (IEC 60264 series).

REDLINE VERSION – 6 – IEC 60851-1:2021+AMD1:2025 CSV
© IEC 2025
WINDING WIRES – TEST METHODS –

Part 1: General
1 Scope
This part of IEC 60851 specifies the general notes on methods of test for winding wires. It also
gives the definitions for terms used in IEC 60851 (all parts). A survey of the contents of
IEC 60851-2 to IEC 60851-6 is given in Annex A.
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.
IEC 60317 (all parts), Specifications for particular types of winding wires
IEC 60851-2:2009 , Winding wires – Test methods – Part 2: Determination of dimensions
IEC 60851-2:2009/AMD1:2015
IEC 60851-2:2009/AMD2:2019
IEC 60851-3:2009 , Winding wires – Test methods – Part 3: Mechanical properties
IEC 60851-3:2009/AMD1:2013
IEC 60851-3:2009/AMD2:2019
IEC 60851-4:2016, Winding wires – Test methods – Part 4: Chemical properties
IEC 60851-5:2008 , Winding wires – Test methods – Part 5: Electrical properties
IEC 60851-5:2008/AMD1:2011
IEC 60851-5:2008/AMD2:2019
IEC 60851-6:2012, Winding wires – Test methods – Part 6: Thermal properties
3 Terms, definitions and general notes on methods of test
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
____________
A consolidated version of IEC 60851-2:2009 and its amendments exists.
A consolidated version of IEC 60851-3:2009 and its amendments exists.
A consolidated version of IEC 60851-5:2008 and its amendments exists.

© IEC 2025
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
bonding layer
material which is deposited on an enamelled wire and which has the specific function of bonding
wires together
3.1.2
bunched wire
winding wire consisting of a quantity of small diameter insulated wires laid-up together without
predetermined geometrical position and with or without additional covering
3.1.3
class
thermal performance of a wire expressed by the temperature index and the heat shock
temperature
3.1.4
coating
material which is deposited on a conductor or wire by suitable means and then dried and/or
cured
3.1.5
conductor
bare metal after removal of the insulation
3.1.6
covering
material which is wound, wrapped or braided around a bare or insulated conductor
3.1.7
crack
opening in the insulation which exposes the conductor to view at the stated magnification
3.1.8
cure
process of converting a reactive compound into a stable, usable condition by polymerization
(polycondensation and polyaddition) and/or crosslinking
[SOURCE: IEC 60050-212:2010, 212-13-07, modified – At the beginning of the definition,
"convert a reactive compound" has been replaced by "process of converting a reactive
compound" to define the term as a process.]
3.1.9
dual coating
insulation composed of two different materials, an underlying and a superimposed coating
3.1.10
enamelled wire
wire coated with an insulation of cured resin
3.1.11
grade
range of increase in dimension of the wire due to insulation

REDLINE VERSION – 8 – IEC 60851-1:2021+AMD1:2025 CSV
© IEC 2025
3.1.12
insulation
coating or covering of the conductor with the specific function of withstanding voltage
3.1.13
nominal conductor dimension
designation of the conductor size in accordance with the specification sheet in the IEC 60317
series
3.1.14
sole coating
insulation composed of one material
3.1.15
winding wire
wire used for winding a coil to provide a magnetic field
3.1.16
wire
conductor coated or covered with an insulation
3.1.17
normal vision
20/20 vision, with corrective lenses, if necessary
3.1.18
zero-defect wire
winding wire that exhibits no electrical discontinuities when tested under specific conditions
3.2 General notes on methods of test
Unless otherwise specified, all tests shall be carried out at a temperature from 15 °C to 40 °C
and a relative humidity of 25 % to 75 %. Before measurements are made, the specimens shall
be preconditioned under these atmospheric conditions for a time sufficient to allow the wire to
reach stability.
The wire to be tested shall be removed from the packaging in such a way that the wire will not
be subjected to tension or to unnecessary bends. Before each test, sufficient wire shall be
discarded to ensure that any damaged wire is not included in the test specimens.
Normally, all mandatory requirements for a method of test are given in the description, and
diagrams are intended only to illustrate one possible arrangement for conducting the test.
In case of inconsistencies between the IEC 60317 specification sheet and this document, the
specification sheet shall prevail.
When the test is restricted only to certain types of winding wires, this is specified with the test.
Those tests of IEC 60851-2, IEC 60851-3, IEC 60851-4, IEC 60851-5 and IEC 60851-6 which
in Annex A are marked with an asterisk are periodic conformance tests. These tests are carried
out at a frequency agreed upon request of the end user.
The test numbers used in IEC 60851-2, IEC 60851-3, IEC 60851-4, IEC 60851-5 and
IEC 60851-6 correspond with the clause numbers in the IEC 60317 series.

© IEC 2025
IEC winding wire standards do not specify how to deal with the management of tests (routine
versus non-routine/periodic). These are certification issues not governed by the standards. In
some countries, there are local rules that apply, but in general, decisions are taken by
agreement between customer and supplier.
The scope of IEC standards encompasses only the product requirements and does not extend
to the management of certification matters or supplier-customer agreements.

REDLINE VERSION – 10 – IEC 60851-1:2021+AMD1:2025 CSV
© IEC 2025
Annex A
(informative)
Contents of IEC 60851-2 to IEC 60851-6 with indication of tests
A.1 General
The tables of contents as given in Clause A.2 to Clause A.6 are not exhaustive.
A.2 IEC 60851-2
The contents shown below refers to IEC 60851-2:2009, IEC 60851-2:2009/AMD1:2015 and
IEC 60851-2:2009/AMD2:2019.
1 Scope
2 Normative references
3 Test 4: Dimensions
3.1 Equipment
3.1.1 Round and rectangular wire
3.1.2 Bunched wire
3.2 Procedure
3.2.1 Conductor dimension
3.2.1.1 Round wire
3.2.1.2 Rectangular wire
3.2.2 Out-of-roundness of the conductor
3.2.3 Rounding of corners of rectangular wire
3.2.4 Increase in dimension due to the insulation
3.2.4.1 Round wire
3.2.4.2 Rectangular wire
3.2.5 Overall dimension
3.2.5.1 Round wire
3.2.5.2 Rectangular wire
3.2.5.3 Bunched wire
3.2.6 Increase in diameter due to the bonding layer of enamelled round wire
3.2.7 Increase in dimensions due to the bonding layer of enamelled rectangular wire
Annex A (informativ
...

IEC 60851-1 ®
Edition 3.0 2021-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Winding wires – Test methods –
Part 1: General
Fils de bobinage – Méthodes d'essai –
Partie 1: Généralités
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International Standards for all electrical, electronic and related technologies.
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latest edition, a corrigendum or an amendment might have been published.
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IEC 60851-1 ®
Edition 3.0 2021-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Winding wires – Test methods –
Part 1: General
Fils de bobinage – Méthodes d'essai –
Partie 1: Généralités
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.060.10 ISBN 978-2-8322-9882-4
– 2 – IEC 60851-1:2021 © IEC 2021
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and general notes on methods of test . 6
3.1 Terms and definitions . 6
3.2 General notes on methods of test . 8
Annex A (informative) Contents of IEC 60851-2 to IEC 60851-6 with indication of tests . 10
A.1 General . 10
A.2 IEC 60851-2 . 10
A.3 IEC 60851-3 . 11
A.4 IEC 60851-4 . 12
A.5 IEC 60851-5 . 13
A.6 IEC 60851-6 . 14
Bibliography . 15

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
WINDING WIRES – TEST METHODS –

Part 1: General
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 60851-1 has been prepared by IEC technical committee 55: Winding wires. It is an
International Standard.
This third edition cancels and replaces the second edition published in 1996, and its
amendment 1:2003 and amendment 2:2009. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) revision to Clause 2 to update the list of normative references;
b) revision to 3.2 atmospheric conditions for testing;
c) addition to 3.2 with remarks concerning frequency and management of tests;
d) revision to Annex A to update the contents list of IEC 60851 series of tests.

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The text of this International Standard is based on the following documents:
FDIS Report on voting
55/1913/FDIS 55/1916/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
Annex A is for information only.
A list of all parts in the IEC 60851 series, published under the general title Winding wires – Test
methods, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
INTRODUCTION
This Part of IEC 60851 forms an element of a series of standards which deals with insulated
wires used for windings in electrical equipment. It is composed of the following series:
1) Winding wires – Test methods (IEC 60851 series);
2) Specifications for particular types of winding wires (IEC 60317 series);
3) Packaging of winding wires (IEC 60264 series).

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WINDING WIRES – TEST METHODS –

Part 1: General
1 Scope
This part of IEC 60851 specifies the general notes on methods of test for winding wires. It also
gives the definitions for terms used in IEC 60851 (all parts). A survey of the contents of
IEC 60851-2 to IEC 60851-6 is given in Annex A.
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.
IEC 60317 (all parts), Specifications for particular types of winding wires
IEC 60851-2:2009 , Winding wires – Test methods – Part 2: Determination of dimensions
IEC 60851-2:2009/AMD1:2015
IEC 60851-2:2009/AMD2:2019
IEC 60851-3:2009 , Winding wires – Test methods – Part 3: Mechanical properties
IEC 60851-3:2009/AMD1:2013
IEC 60851-3:2009/AMD2:2019
IEC 60851-4:2016, Winding wires – Test methods – Part 4: Chemical properties
IEC 60851-5:2008 , Winding wires – Test methods – Part 5: Electrical properties
IEC 60851-5:2008/AMD1:2011
IEC 60851-5:2008/AMD2:2019
IEC 60851-6:2012, Winding wires – Test methods – Part 6: Thermal properties
3 Terms, definitions and general notes on methods of test
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
____________
A consolidated version of IEC 60851-2:2009 and its amendments exists.
A consolidated version of IEC 60851-3:2009 and its amendments exists.
A consolidated version of IEC 60851-5:2008 and its amendments exists.

ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
bonding layer
material which is deposited on an enamelled wire and which has the specific function of bonding
wires together
3.1.2
bunched wire
winding wire consisting of a quantity of small diameter insulated wires laid-up together without
predetermined geometrical position and with or without additional covering
3.1.3
class
thermal performance of a wire expressed by the temperature index and the heat shock
temperature
3.1.4
coating
material which is deposited on a conductor or wire by suitable means and then dried and/or
cured
3.1.5
conductor
bare metal after removal of the insulation
3.1.6
covering
material which is wound, wrapped or braided around a bare or insulated conductor
3.1.7
crack
opening in the insulation which exposes the conductor to view at the stated magnification
3.1.8
cure
process of converting a reactive compound into a stable, usable condition by polymerization
(polycondensation and polyaddition) and/or crosslinking
[SOURCE: IEC 60050-212:2010, 212-13-07, modified – At the beginning of the definition,
"convert a reactive compound" has been replaced by "process of converting a reactive
compound" to define the term as a process.]
3.1.9
dual coating
insulation composed of two different materials, an underlying and a superimposed coating
3.1.10
enamelled wire
wire coated with an insulation of cured resin
3.1.11
grade
range of increase in dimension of the wire due to insulation

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3.1.12
insulation
coating or covering of the conductor with the specific function of withstanding voltage
3.1.13
nominal conductor dimension
designation of the conductor size in accordance with the specification sheet in the IEC 60317
series
3.1.14
sole coating
insulation composed of one material
3.1.15
winding wire
wire used for winding a coil to provide a magnetic field
3.1.16
wire
conductor coated or covered with an insulation
3.1.17
normal vision
20/20 vision, with corrective lenses, if necessary
3.1.18
zero-defect wire
winding wire that exhibits no electrical discontinuities when tested under specific conditions
3.2 General notes on methods of test
Unless otherwise specified, all tests shall be carried out at a temperature from 15 °C to 40 °C
and a relative humidity of 25 % to 75 %. Before measurements are made, the specimens shall
be preconditioned under these atmospheric conditions for a time sufficient to allow the wire to
reach stability.
The wire to be tested shall be removed from the packaging in such a way that the wire will not
be subjected to tension or to unnecessary bends. Before each test, sufficient wire shall be
discarded to ensure that any damaged wire is not included in the test specimens.
Normally, all mandatory requirements for a method of test are given in the description, and
diagrams are intended only to illustrate one possible arrangement for conducting the test.
In case of inconsistencies between the IEC 60317 specification sheet and this document, the
specification sheet shall prevail.
When the test is restricted only to certain types of winding wires, this is specified with the test.
Those tests of IEC 60851-2, IEC 60851-3, IEC 60851-4, IEC 60851-5 and IEC 60851-6 which
in Annex A are marked with an asterisk are periodic conformance tests. These tests are carried
out at a frequency agreed upon request of the end user.
The test numbers used in IEC 60851-2, IEC 60851-3, IEC 60851-4, IEC 60851-5 and
IEC 60851-6 correspond with the clause numbers in the IEC 60317 series.

IEC winding wire standards do not specify how to deal with the management of tests (routine
versus non-routine/periodic). These are certification issues not governed by the standards. In
some countries, there are local rules that apply, but in general, decisions are taken by
agreement between customer and supplier.
The scope of IEC standards encompasses only the product requirements and does not extend
to the management of certification matters or supplier-customer agreements.

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Annex A
(informative)
Contents of IEC 60851-2 to IEC 60851-6 with indication of tests
A.1 General
The tables of contents as given in Clause A.2 to Clause A.6 are not exhaustive.
A.2 IEC 60851-2
The contents shown below refers to IEC 60851-2:2009, IEC 60851-2:2009/AMD1:2015 and
IEC 60851-2:2009/AMD2:2019.
1 Scope
2 Normative references
3 Test 4: Dimensions
3.1 Equipment
3.1.1 Round and rectangular wire
3.1.2 Bunched wire
3.2 Procedure
3.2.1 Conductor dimension
3.2.1.1 Round wire
3.2.1.2 Rectangular wire
3.2.2 Out-of-roundness of the conductor
3.2.3 Rounding of corners of rectangular wire
3.2.4 Increase in dimension due to the insulation
3.2.4.1 Round wire
3.2.4.2 Rectangular wire
3.2.5 Overall dimension
3.2.5.1 Round wire
3.2.5.2 Rectangular wire
3.2.5.3 Bunched wire
3.2.6 Increase in diameter due to the bonding layer of enamelled round wire
3.2.7 Increase in dimensions due to the bonding layer of enamelled rectangular wire
Annex A (informative)
A.3 IEC 60851-3
The contents shown below refers to IEC 60851-3:2009, IEC 60851-3:2009/AMD1:2013 and
IEC 60851-3:2009/AMD2:2019.
1 Scope
2 Normative references
3 Test 6: Elongation
3.1 Elongation at fracture
3.2 Tensile strength
4 Test 7: Springiness
4.1 Round wire with a nominal conductor diameter from 0,080 mm up to and including
1,600 mm
4.2 Round wire with a nominal conductor diameter over 1,600 mm and rectangular wire
5 Test 8: Flexibility and adherence
5.1 Mandrel winding test
5.1.1 Round wire
5.1.2 Rectangular wire
5.1.3 Covered bunched wire
5.2 Stretching test (applicable to enamelled round wire with a nominal conductor diameter
over 1,600 mm)
5.3 Jerk test (applicable to enamelled round wire with a nominal conductor diameter of up
to and including 1,000 mm)
5.4 Peel test (applicable to enamelled round wire with a nominal conductor diameter of over
1,000 mm)
5.5 Adherence test
5.5.1 Enamelled rectangular wire
5.5.2 Impregnated fibre covered round and rectangular wire
5.5.3 Fibre covered enamelled round and rectangular wire
5.5.4 Tape wrapped round and rectangular wire (for adhesive tape only)
6 Test 11*: Resistance to abrasion (applicable to enamelled round wire)
7 Test 18: Heat or solvent bonding (applicable to enamelled round wire with a nominal
conductor diameter over 0,050 mm up to and including 2,000 mm and to enamelled
rectangular wire)
7.1 Vertical bond retention of a helical coil
7.2 Bond strength of a twisted coil
7.3 Enamelled rectangular wire heat bonding
Annex A (informative) – Bond strength of heat bonding wires
Annex B (informative) – Friction test methods

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A.4 IEC 60851-4
The contents shown below refers to IEC 60851-4:2016.
1 Scope
2 Normative references
3 Test 12*: Resistance to solvents (applicable to enamelled round wire with a nominal
conductor diameter of over 0,250 mm and to enamelled rectangular wire)
3.1 Equipment
3.2 Procedure
4 Test 16*: Resistance to refrigerants (applicable to enamelled round wire)
4.1 Extraction
4.2 Breakdown voltage
5 Test 17: Solderability (applicable to enamelled round wire and bunched wire)
5.1 Equipment
5.2 Procedure
6 Test 20*: Resistance to hydrolysis and to transformer oil (applicable to enamelled wire)
6.1 General
6.2 Round wire
6.3 Rectangular wire
Annex A (informative) – Alternative refrigerants to monochloro-difluoromethane

A.5 IEC 60851-5
The contents shown below refers to IEC 60851-5:2008, IEC 60851-5:2008/AMD1:2011 and
IEC 60851-5:2009/AMD2:2019.
1 Scope
2 Normative references
3 Test 5: Electrical resistance
4 Test 13: Breakdown voltage
4.1 Principle
4.2 Equipment
4.3 Enamelled round wire
4.4 Enamelled round wire with a nominal conductor diameter over 0,100 mm and up to and
including 2,500 mm, grade 1 to grade 3
4.5 Round wire with a nominal conductor diameter over 2,500 mm
4.6 Fibre wound round wire
4.7 Rectangular wire
5 Test 14: Continuity of insulation (applicable to enamelled round and tape wrapped round
wire)
5.1 General
5.2 Low-voltage continuity (nominal conductor diameter up to and including 0,050 mm,
grade 1 to grade 3)
5.3 High-voltage continuity (nominal conductor diameter over 0,050 mm up to and including
1,600 mm, grade 1 to grade 3, and over 0,035 mm, up to and including 1,600 mm, grade
3 of FIW 3 to FIW 9)
5.4 Inline high-volt
...