IEC 60974-7:2019

Arc welding equipment - Part 7: Torches

IEC 60974-7:2019 specifies safety and construction requirements for torches used for arc welding and allied processes. This document is applicable to manual, mechanically guided, air-cooled, liquid-cooled, motorized, spool-on and fume extraction torches.
This fourth edition cancels and replaces the third edition published in 2013 and constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) definitions 3.11 and 3.20 were revised;
b) requirements for arc striking and stabilizing voltage rating have been added to the sequence of type tests (see 6.2);
c) the AC test voltage requirement for torches that utilize arc striking and stabilizing voltageshas been revised (see 7.5.2);
d) the test configuration of isolated circuits for torches that utilize arc striking and stabilizing voltages has been revised (see 7.5.2);
e) the metal tube used for the heating tests has additional allowable means of cooling methods (see 8.3.2 and 8.3.5);
f) for fume extraction torches, the instructions for use include additional information (see Clause 13, item i)).
This document is to be used in conjunction with IEC 60974-1:2017.

Matériel de soudage à l'arc - Partie 7: Torches

L’IEC 60974-7:2019 spécifie les exigences de sécurité et de construction pour les torches utilisées en soudage à l’arc et les procédés connexes. Le présent document s’applique aux torches manuelles, guidées mécaniquement, refroidies par air, refroidies par liquide, motorisées, enroulées et pour extraction de fumée.
Cette quatrième édition annule et remplace la troisième édition parue en 2013 et constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) les définitions 3.11 et 3.20 ont été révisées;
b) les exigences relatives aux caractéristiques assignées de la tension d’amorçage et de stabilisation de l’arc ont été ajoutées à la séquence des essais de type (voir 6.2);
c) les exigences de tension d’essai en courant alternatif pour les torches qui utilisent des tensions d’amorçage et de stabilisation de l’arc ont été révisées (voir 7.5.2)
d) la configuration d’essai des circuits isolés pour les torches qui utilisent des tensions d’amorçage et de stabilisation de l’arc a été révisée (voir 7.5.2);
e) le tube métallique utilisé pour les essais d’échauffement est équipé de moyens supplémentaires de refroidissement autorisés (voir 8.3.2 et 8.3.5);
f) les instructions d’emploi des torches pour extraction de fumée incluent des informations additionnelles (voir Article 13, point i)).
Ce document doit être utilisé conjointement avec l’IEC 60974-1:2017.

General Information

• Status: Published
• Publication Date: 29-Jan-2019
• ICS: 25.160.30 - Welding equipment
• Technical Committee: TC 26 - Electric welding
• Drafting Committee: WG 1 - TC 26/WG 1
• Current Stage: PPUB - Publication issued
• Start Date: 30-Jan-2019
• Completion Date: 22-Feb-2019

Relations

• Revises: IEC 60974-7:2013 - Arc welding equipment - Part 7: Torches
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60974-7 ®
Edition 4.0 2019-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Arc welding equipment –
Part 7: Torches
Matériel de soudage à l’arc –
Partie 7: Torches
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.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and
If you wish to give us your feedback on this publication or CISPR.

need further assistance, please contact the Customer Service

Centre: [e-mail].
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC - Electropedia - www.electropedia.org
webstore.iec.ch/advsearchform Le premier dictionnaire d'électrotechnologie en ligne au
La recherche avancée permet de trouver des publications IEC monde, avec plus de 22 000 articles terminologiques en
en utilisant différents critères (numéro de référence, texte, anglais et en français, ainsi que les termes équivalents dans
comité d’études,…). Elle donne aussi des informations sur les 16 langues additionnelles. Egalement appelé Vocabulaire
projets et les publications remplacées ou retirées. Electrotechnique International (IEV) en ligne.

IEC Just Published - webstore.iec.ch/justpublished Glossaire IEC - std.iec.ch/glossary
Restez informé sur les nouvelles publications IEC. Just 67 000 entrées terminologiques électrotechniques, en anglais
Published détaille les nouvelles publications parues. et en français, extraites des articles Termes et Définitions des
Disponible en ligne et une fois par mois par email. publications IEC parues depuis 2002. Plus certaines entrées
antérieures extraites des publications des CE 37, 77, 86 et
Service Clients - webstore.iec.ch/csc CISPR de l'IEC.

Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
[e-mail].
IEC 60974-7 ®
Edition 4.0 2019-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Arc welding equipment –
Part 7: Torches
Matériel de soudage à l’arc –
Partie 7: Torches
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.160.30 ISBN 978-2-8322-6500-0

– 2 – IEC 60974-7:2019 © IEC 2019
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Environmental conditions . 9
5 Classification . 10
5.1 General . 10
5.2 Process . 10
5.3 Guidance . 10
5.4 Cooling . 10
5.5 Main arc striking for plasma processes . 10
6 Test conditions . 10
6.1 General . 10
6.2 Type tests . 11
6.3 Routine tests. 11
7 Protection against electric shock . 11
7.1 Voltage rating . 11
7.2 Insulation resistance . 12
7.3 Dielectric strength . 13
7.3.1 General requirement . 13
7.3.2 Additional requirements for plasma cutting TORCHES . 13
7.4 Protection against electric shock in normal service (direct contact) . 13
7.4.1 Degree of protection requirements . 13
7.4.2 Additional requirements for plasma cutting TORCHES . 13
7.5 Requirements for ARC STRIKING AND STABILIZING VOLTAGE rating . 14
7.5.1 General requirement . 14
7.5.2 ARC STRIKING AND STABILIZING VOLTAGE test . 14
8 Thermal rating . 15
8.1 General . 15
8.2 Temperature rise . 15
8.3 Heating test . 15
8.3.1 General . 15
8.3.2 Metal inert/active gas (MIG/MAG) or self-shielded flux-cored arc
welding TORCH . 16
8.3.3 Tungsten inert gas (TIG) and plasma arc welding TORCH . 18
8.3.4 Plasma cutting TORCH . 19
8.3.5 Submerged arc welding TORCH . 19
9 Pressure of the liquid cooling system . 20
10 Resistance to hot objects . 20
11 Mechanical provisions . 21
11.1 Impact resistance . 21
11.2 Accessible parts. 22
11.3 HANDLE material . 22
12 Marking . 22
13 Instructions for use . 22

Annex A (informative) Additional terminology . 24
Annex B (normative) Position of the welding TORCHES for the heating test. 27
Annex C (informative) Cooled copper block . 28
Annex D (informative) Copper block with a hole . 29
Annex E (informative) Copper bars with a slot . 30
Bibliography . 31

Figure 1 – Device for testing the resistance to hot objects . 20
Figure 2 – Device for the impact test . 21
Figure A.1 – TORCH for metal inert/active gas (MIG/MAG) or self-shielded flux-cored
arc welding . 25
Figure A.2 – GUN for metal inert/active gas (MIG/MAG) or self-shielded flux-cored arc
welding . 25
Figure A.3 – TORCH for tungsten inert gas arc welding . 25
Figure A.4 – TORCH for plasma arc welding . 25
Figure A.5 – TORCH for plasma cutting . 26
Figure A.6 – Supply unit . 26
Figure A.7 – MECHANICALLY GUIDED plasma TORCH . 26
Figure B.1 – MIG/MAG TORCHES . 27
Figure B.2 – TIG TORCHES . 27
Figure B.3 – Plasma welding TORCHES . 27
Figure C.1 – Water-cooled copper block – Example . 28
Figure D.1 – Water-cooled copper block with a hole – Example . 29
Figure E.1 – Water-cooled copper bars with a slot – Example . 30

TORCHES . 12
Table 1 – Voltage rating of
Table 2 – Test values for metal inert gas arc welding (MIG) of aluminium alloys . 16
Table 3 – Test values for metal active gas arc welding (MAG) of mild steel . 17
Table 4 – Test values for metal active gas arc welding (MAG) with flux-cored wire . 17
Table 5 – Test values for self-shielded flux-cored arc welding of mild steel . 18
Table 6 – Test values for tungsten inert gas arc welding (TIG) . 18
Table 7 – Test values for plasma arc welding . 19
Table A.1 – List of terms . 24

– 4 – IEC 60974-7:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ARC WELDING EQUIPMENT –
Part 7: Torches
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.
International Standard IEC 60974-7 has been prepared by IEC technical committee 26:
Electric welding.
This fourth edition cancels and replaces the third edition published in 2013 and constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) definitions 3.11 and 3.20 were revised;
b) requirements for ARC STRIKING AND STABILIZING VOLTAGE rating have been added to the
sequence of type tests (see 6.2);
c) the AC test voltage requirement for TORCHES that utilize ARC STRIKING AND STABILIZING
VOLTAGES has been revised (see 7.5.2);

d) the test configuration of isolated circuits for TORCHES that utilize ARC STRIKING AND
STABILIZING VOLTAGES has been revised (see 7.5.2);
e) the metal tube used for the heating tests has additional allowable means of cooling
methods (see 8.3.2 and 8.3.5);
f) for FUME EXTRACTION TORCHES, the instructions for use include additional information
(see Clause 13, item i)).
The text of this International Standard is based on the following documents:
FDIS Report on voting
26/673/FDIS 26/678/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
In this standard, the following print types are used:
– conformity statements: in italic type;
– terms used throughout this standard which have been defined in clause 3: SMALL ROMAN
CAPITALS.
This document is to be used in conjunction with IEC 60974-1:2017.
A list of all parts in the IEC 60974 series, published under the general title Arc welding
equipment, 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.
– 6 – IEC 60974-7:2019 © IEC 2019
ARC WELDING EQUIPMENT –
Part 7: Torches
1 Scope
This part of IEC 60974 specifies safety and construction requirements for TORCHES used for
arc welding and allied processes. This document is applicable to MANUAL, MECHANICALLY
GUIDED, AIR-COOLED, LIQUID-COOLED, MOTORIZED, SPOOL-ON and FUME EXTRACTION TORCHES.
In this document, a TORCH consists of the TORCH BODY, the CABLE-HOSE ASSEMBLY and other
components.
This document is also applicable to a CABLE-HOSE ASSEMBLY connected between a power
source and ancillary equipment.
This document is not applicable to electrode holders for manual metal arc welding or air-arc
cutting/gouging.
NOTE 1 Typical allied processes are electric arc cutting and arc spraying.
NOTE 2 Other components are listed in Table A.1.
NOTE 3 In this document, all procedures and requirements are the same for “TORCHES” and “GUNS”. For
convenience, the term "TORCH" is used in the following text.
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 60529, Degrees of protection provided by enclosures (IP Code)
IEC 60695-11-10, Fire hazard testing – Part 11-10: Test flames – 50 W horizontal and vertical
flame test methods
IEC 60974-1:2017, Arc welding equipment – Part 1: Welding power sources
ISO 21904-3:2018, Health and safety in welding and allied processes – Requirements, testing
and marking of equipment for air filtration – Part 3: Determination of the capture efficiency of
on-torch welding fume extraction devices
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60974-1, as well as
the following apply.
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
NOTE Additional terminology is given in Annex A.
3.1
torch
device that conveys all services necessary to the arc for welding, cutting or allied processes
(for example, current, gas, coolant, ELECTRODE WIRE)
[SOURCE: IEC 60050-851:2008, 851-14-21]
3.2
gun
TORCH with a HANDLE substantially perpendicular to the TORCH BODY
[SOURCE: IEC 60050-851:2008, 851-14-22]
3.3
torch body
main component to which the CABLE-HOSE ASSEMBLY and other components are connected
[SOURCE: IEC 60050-851:2008, 851-14-29]
3.4
handle
part designed to be held in the operator's hand
[SOURCE: IEC 60050-851:2008, 851-14-28, modified – The statement “of a TORCH or an
electrode holder” after the term is deleted.]
3.5
gas nozzle
TORCH directing the shielding gas around the arc and over
component at the exit end of the
the weld pool
[SOURCE: IEC 60050-851:2008, 851-14-56]
3.6
wire electrode
solid or tubular FILLER WIRE which conducts welding current
[SOURCE: IEC 60050-851:2008, 851-14-02]
3.7
contact tip
replaceable metal component fixed at the front end of the TORCH, which transfers the welding
current to, and guides, the WIRE ELECTRODE
[SOURCE: IEC 60050-851:2008, 851-14-17]
3.8
cable-hose assembly
flexible assembly of cables and hoses, and their connecting elements, that delivers supplies
to the TORCH BODY or ancillary equipment

– 8 – IEC 60974-7:2019 © IEC 2019
[SOURCE: IEC 60050-851:2008, 851-14-34, modified – The definition is expanded to include
ancillary equipment and the word “supplies” is used instead of “all necessary services”.
3.9
manual torch
TORCH held and guided by the operator's hand during its operation
[SOURCE: IEC 60050-851:2008, 851-14-24]
3.10
mechanically guided torch
TORCH fixed to, and guided by, a mechanical device during its operation
[SOURCE: IEC 60050-851:2008, 851-14-25]
3.11
air-cooled torch
TORCH cooled by the ambient air and, where appropriate, by gas flow
3.12
liquid-cooled torch
TORCH cooled by the circulation of a cooling liquid
3.13
motorized torch
TORCH incorporating means to supply motion to the WIRE ELECTRODE
[SOURCE: IEC 60050-851:2008, 851-14-26]
3.14
spool-on torch
MOTORIZED TORCH incorporating a FILLER WIRE supply
[SOURCE: IEC 60050-851:2008, 851-14-27]
3.15
arc striking and stabilizing voltage
voltage superimposed on the welding circuit to initiate or maintain the arc or both
3.16
filler metal
metal added during welding or allied processes
[SOURCE: IEC 60050-851:2008, 851-14-43]
3.17
filler wire
FILLER METAL, in solid or tubular wire form, which may or may not be part of the welding circuit
[SOURCE: IEC 60050-851:2008, 851-14-44]
3.18
plasma tip
component that provides the constricting orifice through which the plasma arc passes
[SOURCE: IEC 60050-851:2008, 851-14-18]

3.19
visual inspection
inspection by eye to verify that there are no apparent discrepancies with respect to the
provisions of the standard concerned
[SOURCE: IEC 60050-851:2008, 851-11-11]
3.20
plasma cutting system
combination of power source, TORCH, and associated devices for plasma cutting/gouging
[SOURCE: IEC 60050-851:2008, 851-13-03, modified – The word “safety” is deleted between
the words “associated” and “devices”.]
3.21
plasma cutting power source
equipment for supplying current and voltage and having the required characteristics suitable
for plasma cutting/gouging and which may supply gas and cooling liquid
Note 1 to entry: A PLASMA CUTTING POWER SOURCE may also supply services to other equipment and auxiliaries,
for example auxiliary power, cooling liquid, and gas.
[SOURCE: IEC 60050-851:2008, 851-13-04, modified – The word “electric” is deleted before
the word “current”.]
3.22
torch coupling device
part of TORCH connecting the CABLE-HOSE ASSEMBLY to the welding equipment
Note 1 to entry: A TORCH COUPLING DEVICE may include several connecting parts.
3.23
fume extraction torch
TORCH that incorporates means to capture the welding fumes
4 Environmental conditions
TORCHES shall be capable of operation when the following environmental conditions prevail:
a) range of ambient air temperature:
during operation: –10 °C to +40 °C;
b) relative humidity of the air:
up to 50 % at 40 °C;
up to 90 % at 20 °C.
TORCHES shall withstand storage and transport at an ambient air temperature of –20 °C to
+55 °C without any damage to function and performance.
NOTE Different environmental conditions can be agreed upon between the manufacturer and the purchaser.
Examples of these conditions are: high humidity, unusually corrosive fumes, steam, excessive oil vapour, abnormal
vibration or shock, excessive dust, severe weather conditions, unusual coastal or shipboard conditions, vermin
infestation and atmospheres conducive to the growth of mould.

– 10 – IEC 60974-7:2019 © IEC 2019
5 Classification
5.1 General
TORCHES shall be classified in accordance with:
a) the process for which they are designed, see 5.2;
b) the method by which they are guided, see 5.3;
c) the type of cooling, see 5.4;
d) the method of striking the main arc for plasma processes, see 5.5.
5.2 Process
TORCHES can be designed for:
a) MIG/MAG welding;
b) self-shielded flux-cored arc welding;
c) TIG welding;
d) plasma welding;
e) submerged arc welding;
f) plasma cutting/gouging.
5.3 Guidance
Methods of TORCH guidance:
a) manual;
b) mechanical.
5.4 Cooling
Type of TORCH cooling method:
a) ambient air or shielding gas, see 3.11;
b) liquid, see 3.12.
5.5 Main arc striking for plasma processes
Methods for striking the main arc:
a) by an arc striking voltage;
b) by a pilot arc;
c) by contact.
6 Test conditions
6.1 General
Tests shall be carried out on new and completely assembled TORCHES, fitted with the
CABLE-HOSE ASSEMBLY normally supplied.
All tests shall be carried out at any ambient air temperature given in Clause 4, item a).
The accuracy of measuring instruments shall be:

a) electrical measuring instruments: class 1 (± 1 % of full-scale reading), except for the
measurement of insulation resistance and dielectric strength where the accuracy of the
instruments is not specified, but shall be taken into account for the measurement;
b) temperature measuring device: ± 2 K.
6.2 Type tests
Unless otherwise specified, the tests in this document are type tests.
The type tests given below shall be carried out on the same sample and in the following
sequence:
a) general VISUAL INSPECTION;
b) insulation resistance (preliminary check), see 7.2 without humidity treatment;
c) impact resistance, see 11.1;
d) resistance to hot objects, see Clause 10;
e) protection against direct contact, see 7.4;
f) insulation resistance, see 7.2;
g) dielectric strength, see 7.3;
h) requirements for ARC STRIKING AND STABILIZING VOLTAGE rating, see 7.5;
i) general VISUAL INSPECTION.
The heating test in accordance with 8.3 may be carried out on a separate sample and shall be
followed by the coolant leakage test in accordance with Clause 9. The other tests included in
this document and not listed here may be carried out in any convenient sequence.
6.3 Routine tests
The following routine tests shall be carried out on each TORCH in the following sequence:
a) general VISUAL INSPECTION;
b) functional test as specified by the manufacturer, for example, leaks of fluid or gas, trigger
operation.
7 Protection against electric shock
7.1 Voltage rating
TORCHES shall be rated according to the classification and use as given in Table 1.

– 12 – IEC 60974-7:2019 © IEC 2019
Table 1 – Voltage rating of TORCHES
Classification Voltage Insulation Dielectric Degree of protection in
rating resistance strength accordance with IEC 60529
V MΩ V RMS
peak
NOZZLE HANDLE TORCH Other
b, c
orifice COUPLING parts
a
DEVICE
Manually guided 113 1 1 000 IP0X IP3X IP2X IP3X
TORCHES except for
plasma cutting
MECHANICALLY GUIDED 141 1 1 000 IP0X Not IPXX IP2X
TORCHES except for
applicable
plasma cutting and
submerged arc welding
MECHANICALLY GUIDED Not
141 1 1 000 IP0X IPXX IPXX
submerged arc welding applicable
TORCHES
Manually guided plasma 500 2,5 2 100 PLASMA IP4X IP3X IP3X
cutting TORCHES TIP, see
7.4.2
MECHANICALLY GUIDED 500 2,5 2 100 IP0X Not IP2X IP2X
plasma cutting TORCHES applicable
a
Degree of protection for TORCH COUPLING DEVICE is tested while coupled.
b
Other parts are, for example, GAS NOZZLE, neck.
c
Wire drive systems of MOTORIZED TORCHES that are accessible to touch are not considered as other parts:
IPXX.
7.2 Insulation resistance
The insulation resistance of a new TORCH shall, after the humidity treatment, be not less than
the values given in Table 1.
Conformity shall be checked by the following test:
a) Humidity treatment
A humidity cabinet is maintained at a temperature t between 20 °C and 30 °C and a
relative humidity between 91 % and 95 %.
TORCH fitted with the CABLE-HOSE ASSEMBLY (LIQUID-COOLED TORCHES without cooling
The
liquid) is brought to a temperature between t and (t + 4) °C and is then placed for 48 h in
the humidity cabinet.
b) Insulation resistance measurement
Immediately after the humidity treatment, the TORCH HANDLE and 1 m at each end of the
CABLE-HOSE ASSEMBLY are wiped clean and tightly wrapped in a metal foil covering the
external surface of the insulation.
The insulation resistance is measured by the application of a DC voltage of 500 V between
– all circuits and the metal foil,
and
– all wires and circuits intended to be isolated from each other within the TORCH.
The reading is made after stabilization of the measurement.

7.3 Dielectric strength
7.3.1 General requirement
The insulation shall withstand the test voltages of Table 1 without any flashover or
breakdown.
The AC test voltage shall be of an approximate sine waveform with a peak value not
exceeding 1,45 times the voltage of Table 1, having a frequency of approximately 50 Hz or
60 Hz. Alternatively, a DC test voltage of 1,4 times the RMS test voltage may be used.
Conformity shall be checked by the following test:
LIQUID-COOLED TORCHES are tested without cooling liquid.
The HANDLES are tightly wrapped with a metal foil. The CABLE-HOSE ASSEMBLY is placed in
contact with a conductive surface throughout its entire length, for example wrapped around a
metal cylinder or coiled on a flat metal surface. The metal foil and the conductive surface are
electrically connected.
The full value of the test voltage is applied for 60 s between:
a) the conductive surface and each isolated circuit;
b) all circuits intended to be isolated from each other (e.g. trigger or other remote control
circuits).
At the discretion of the manufacturer, the test voltage may be slowly raised to the full value.
The maximum permissible setting of the overload release shall be 100 mA. The high-voltage
transformer shall deliver the prescribed voltage up to the tripping current. Tripping is regarded
as a flashover or breakdown.
NOTE For the operator’s safety, the lowest setting of the tripping current (less than or equal to 10 mA) is typical.
7.3.2 Additional requirements for plasma cutting TORCHES
In addition for manual plasma cutting TORCHES the insulation between the HANDLE and the
cutting circuit shall withstand a test voltage of 3 750 V RMS During the dielectric strength test
of plasma cutting TORCHES, the electrode and PLASMA TIP connections shall be electrically
connected together.
Conformity shall be checked by the test given in 7.3.1.
7.4 Protection against electric shock in normal service (direct contact)
7.4.1 Degree of protection requirements
TORCHES shall meet the degree of protection requirements of Table 1. In addition CABLE-HOSE
ASSEMBLY shall meet the degree of protection IP 3X. TORCHES are not intended for operation
during rain or snow or equivalent conditions.
Conformity shall be checked in accordance with IEC 60529.
7.4.2 Additional requirements for plasma cutting TORCHES
The plasma cutting TORCH, parts (e.g. parts typically replaced due to wear) and PLASMA
CUTTING POWER SOURCE, recommended by the manufacturer, shall form a safe system.

– 14 – IEC 60974-7:2019 © IEC 2019
Additional requirements for plasma cutting TORCHES are given in 6.3.4 of IEC 60974-1:2017.
7.5 Requirements for ARC STRIKING AND STABILIZING VOLTAGE rating
7.5.1 General requirement
TORCHES intended for use with arc striking and stabilizing devices shall have an ARC STRIKING
AND STABILIZING VOLTAGE rating.
For tungsten inert gas (TIG) and plasma arc welding TORCHES the rated ARC STRIKING and/or
STABILIZING VOLTAGE shall be determined by the manufacturer.
For plasma cutting TORCHES, the rated ARC STRIKING and/or STABILIZING VOLTAGE shall be
determined as follows:
a) operate each power source expected to form a safe system (see item p) of Clause 13)
according to manufacturer's recommendation, for example with proper consumables and
gasses, and under single fault condition;
b) measure the ARC STRIKING and/or STABILIZING VOLTAGE at each end of the TORCH;
c) the highest value measured, from all power sources operated in item a), will be the rated
ARC STRIKING and/or STABILIZING VOLTAGE.
RC STRIKING AND STABILIZING VOLTAGE test
7.5.2 A
The TORCH insulation shall withstand a test voltage without flashover or breakdown. Corona
discharges are permitted.
LIQUID-COOLED TORCHES may be tested without cooling liquid.
Conformity shall be checked by the following test:
The TORCH HANDLE is tightly wrapped with a metal foil. The cable and hose assembly is placed
in contact with a conductive surface throughout its entire length, for example wrapped around
a metal cylinder or coiled on a flat metal surface. The metal foil and the conductive surface
are electrically connected.
A test voltage with a peak voltage 20 % higher than the rated ARC STRIKING AND STABILIZING
VOLTAGE is applied for 2 s between the TORCH electrode and the conductive surface. Other
isolated circuits may be connected to the TORCH electrode, the conductive surface or left
isolated as specified by the manufacturer. The equipment manufacturer shall conduct a risk
assessment of the other isolated circuitry and respective external parts.
Circuits other than the cutting circuit that leave the plasma cutting TORCH may be electrically
connected to the electrode or isolated during this test, provided that the external parts of the
other circuit have reinforced insulation to protect the operator. Additionally, the equipment
manufacturer shall conduct an appropriate risk assessment and establish a set of measures
which give sufficient protection against electric shock under single-fault conditions.
This test voltage is either:
a) high-frequency voltage of pulse width between 0,2 µs and 8 µs, with a repetition frequency
between 50 Hz and 300 Hz; or
b) an AC test voltage with the same peak value of approximately sine waveform at 50 Hz or
60 Hz. The maximum permissible setting of the tripping current shall be 100 mA. The high
voltage transformer shall deliver the prescribed voltage up to the tripping current. Tripping
is regarded as a flashover or a breakdown.
NOTE For the operator’s safety, the lowest setting of the tripping current (less than or equal to 10 mA) is typical.

8 Thermal rating
8.1 General
MANUAL TORCHES shall be rated at a minimum of 100 % or 60 % or 35 % duty cycle.
MECHANICALLY GUIDED TORCHES shall be rated at a minimum of 100 % duty cycle.
FUME EXTRACTION TORCHES shall be rated at the extraction flow rate defined by the
manufacturer.
8.2 Temperature rise
The temperature rise of MANUAL TORCHES, at any point on the outer surface of the part of the
HANDLE gripped by the operator, shall not exceed 30 K.
The temperature rise of CABLE-HOSE ASSEMBLY, at any point on the outer surface, shall not
exceed 40 K.
After completion of the tests, the safety and operability of the TORCH shall not be impaired.
Conformity shall be checked by the heating test according to 8.3.
8.3 Heating test
8.3.1 General
TORCHES shall be loaded with all rated currents at their corresponding rated duty cycles,
The
see 8.1.
The mean value of the DC current shall be taken and the electrode polarity shall be chosen in
accordance with 8.3.2 and 8.3.3.
The temperature shall be measured at the hottest spot on the area of the HANDLE, normally
gripped by the operator for MANUAL TORCHES.
The temperature shall be measured at the hottest spot of CABLE-HOSE ASSEMBLY.
The temperature measuring device(s), HANDLE and CABLE-HOSE ASSEMBLY shall be protected
from draughts and radiant heat.
The TORCH clamping device used shall not significantly affect the test result, for example by
heat loss.
LIQUID-COOLED TORCHES shall be continuously cooled with the minimum flow rate and
minimum cooling power as specified by the manufacturer (see item h) of Clause 13).
NOTE Cooling power is defined in IEC 60974-2.
Each heating test shall be carried out for a period of not less than 30 min and continued until
the rate of temperature rise does not exceed 2 K/h.
The cycle time for test purposes shall be 10 min.
The ambient and TORCH temperature shall be measured simultaneously during the last 10 min
in the case of continuous load (100 % duty cycle). For lower duty cycles, it shall be measured
in the middle of the load period during the last cycle.

– 16 – IEC 60974-7:2019 © IEC 2019
The ambient air temperature is measured by a device, located at a distance of 2 m, at the
same height as the TORCH and shall be protected from draughts and radiant heat.
8.3.2 Metal inert/active gas (MIG/MAG) or self-shielded flux-cored arc welding TORCH
A metal tube of a diameter and length appropriate to the welding process, for example
400 mm in diameter and 500 mm long, is horizontally clamped into a rotating device. The
inside of the tube is cooled by some means, for example by water or air.
The TORCH shall be positioned in a plane perpendicular to the tube axis in such a way that the
WIRE ELECTRODE is 15 ° to the vertical (see Figure B.1). In addition, for manually guided
−15
TORCHES, the HANDLE shall be positioned on the cooler side.
The TORCH shall be moved parallel to the centre line of the tube in order to form a weld bead.
a) Test conditions for metal inert gas arc welding (MIG) of aluminium alloys are given below
and in Table 2:
– WIRE ELECTRODE: aluminium, 3 % to 5 % magnesium;
– type of current: DC;
– electrode polarity: positive;
– shielding gas: argon;
– tube material: aluminium alloy;
– load voltage and welding speed: adjusted to give a stable arc and a continuous
weld pool.
Table 2 – Test values for metal inert gas arc welding (MIG) of aluminium alloys
Welding current Nominal diameter Distance between Maximum gas flow
of the WIRE ELECTRODE CONTACT TIP and metal
tube ± 20 %
A mm mm l/min
Up to 150 0,8 10 10
151 to 200 1 15 12
201 to 300 1,2 18 15
301 to 350 1,6 22 18
351 to 500 2 26 20
Above 500 2,4 28 20
b) Test conditions for metal active gas arc welding (MAG) of mild steel are given below and
in Table 3:
– WIRE ELECTRODE: copper-coated mild (low carbon) steel;
– type of current: DC;
– electrode polarity: positive;
– shielding gas: argon/CO mixed gas (15 % to 25 % CO );
2 2
– tube material: mild (low carbon) steel;
– load voltage and welding speed: adjusted to give a stable arc and a continuous
weld pool.
If additional values for the shielding gas CO are specified in the instructions for use, an
additional test with this gas shall be carried out according to the test conditions given
in Table 3.
Table 3 – Test values for metal active gas arc welding (MAG) of mild steel
Welding Nominal diameter of the Distance between Maximum gas flow
current WIRE ELECTRODE CONTACT TIP and metal
tube ± 20 %
A mm mm l/min
Up to 150 0,8 10 10
151 to 250 1 15 13
251 to 350 1,2 18 15
351 to 500 1,6 22 20
Above 500 2 26 25
c) Test conditions for metal active gas arc welding (MAG) with flux-cored wire are given
below and in Table 4:
– WIRE ELECTRODE: rutile type;
– type of current: DC;
– electrode polarity: positive;
– shielding gas: argon/CO mixed gas (15 % to 25 % CO );
2 2
– tube material: mild (low carbon) steel;
– load voltage and welding speed: adjusted to give a stable arc and a continuous
weld pool.
Table 4 – Test values for metal active gas arc welding (MAG) with flux-cored wire
Welding Nominal diameter Distance between CONTACT TIP Maximum gas
current of the WIRE ELECTRODE flow
and metal tube ± 20 %
A mm mm l/min
251 to 350 1,2 to 1,4 25 15
351 to 500 1,6 to 2 30 18
Above 500 2,4 35 20
d) Test conditions for self-shielded flux-cored arc welding of mild steel are given below and
in Table 5:
– WIRE ELECTRODE: type 1: a wire designed with a fast freezing slag
for all-positional welding;
type 2: a wire designed for high deposition rates
in flat and horizontal vertical position welding;
– type of current: DC;
– electrode polarity: WIRE ELECTRODE ty
...