oSIST prEN ISO 472-3:2026

• Abstract:

  The ISO 472 series defines terms used in the plastics industry, including terms and definitions appearing in the plastics standards of ISO/TC 61 and general terms and definitions of polymer science used in all aspects of plastics technology.; This document defines terms used in the plastics standards of ISO TC61/SC11 Plastics Products and relevant terms applied in the area of welding (including solvent welding) and thermal staking.

• Status: Not Published
• Public Enquiry End Date: 24-Dec-2026
• ICS: 01.040.83 - Rubber and plastics industries (Vocabularies)
• ICS: 83.080.01 - Plastics in general
• Technical Committee: IPMA - Polimer materials and products
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 26-Oct-2026
• Due Date: 15-Mar-2027
• Ref Project: prEN ISO 472-3 - Plastics - Vocabulary - Part 3: Welding and thermal staking of plastics (ISO/DIS 472‑3:2026)

• Revises: SIST EN ISO 472:2014/A1:2019 - Plastics - Vocabulary - Amendment 1: Additional items (ISO 472:2013/Amd 1:2018)
• Effective Date: 02-Jul-2025
• Revises: SIST EN ISO 472:2014 - Plastics - Vocabulary (ISO 472:2013)
• Effective Date: 02-Jul-2025

SLOVENSKI STANDARD
01-december-2026
Polimerni materiali - Slovar - 3. del: Varjenje in toplotno spajanje plastike (ISO/DIS
472-3:2026)
Plastics - Vocabulary - Part 3: Welding and thermal staking of plastics (ISO/DIS 472-
3:2026)
Kunststoffe - Fachwörterverzeichnis - Teil 3: Thermisches Fügen von Kunststoffen
(ISO/DIS 472-3:2026)
Plastiques - Vocabulaire - Partie 3: Soudage et collage thermique des plastiques
(ISO/DIS 472-3:2026)
Ta slovenski standard je istoveten z: prEN ISO 472-3
ICS:
01.040.83 Gumarska industrija in Rubber and plastics
industrija polimernih industries (Vocabularies)
materialov (Slovarji)
83.080.01 Polimerni materiali na Plastics in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 472-3
ISO/TC 61/SC 11
Plastics — Vocabulary —
Secretariat: JISC
Part 3:
Voting begins on:
Welding and thermal staking of 2026-10-08
plastics
Voting terminates on:
2026-12-31
Plastiques — Vocabulaire —
Partie 3: Soudage et collage thermique des plastiques
ICS: 01.040.83; 83.080.01
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
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Reference number
ISO/DIS 472-3:2026(en)
DRAFT
ISO/DIS 472-3:2026(en)
International
Standard
ISO/DIS 472-3
ISO/TC 61/SC 11
Plastics — Vocabulary —
Secretariat: JISC
Part 3:
Voting begins on:
Welding and thermal staking of
plastics
Voting terminates on:
Plastiques — Vocabulaire —
Partie 3: Soudage et collage thermique des plastiques
ICS: 01.040.83; 83.080.01
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document has not been edited by the ISO Central Secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
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Published in Switzerland Reference number
ISO/DIS 472-3:2026(en)
ii
ISO/DIS 472-3:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Terms related to welding processes .1
3.1.1 General terms .1
3.1.2 Welding processes.2
3.1.3 Characterization of welds .14
3.1.4 Imperfections . 15
3.1.5 Type of joint . 23
3.1.6 Joint preparation .24
3.1.7 Welding execution . 25
3.1.8 Welding consumables . 28
3.1.9 Material properties related to welding . 30
3.2 Terms related to testing .31
3.3 Terms related to welding equipment . 36
3.4 Terms related to welding parameters .41
3.5 Terms related to welding management, personnel and organization . 48
Annex A (informative) Terms that are relevant to the welding and thermal joining of plastics
and are defined in other documents .50
Bibliography .53
Index .55

iii
ISO/DIS 472-3:2026(en)
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).
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/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 61, [Plastics], Subcommittee SC 11, [Products]
in collaboration with Commission VI, Terminology, of the International Institute of Welding (IIW).
A list of all parts in the ISO 472 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/DIS 472-3:2026(en)
Introduction
The following information is included for each term in each of the three languages currently available
(English, French and German):
— term ID – unique for each term;
— term;
— definition;
— note (where applicable).
v
DRAFT International Standard ISO/DIS 472-3:2026(en)
Plastics — Vocabulary —
Part 3:
Welding and thermal staking of plastics
1 Scope
The ISO 472 series defines terms used in the plastics industry, including terms and definitions appearing in
the plastics standards of ISO/TC 61 and general terms and definitions of polymer science used in all aspects
of plastics technology.
This document defines terms used in the plastics standards of ISO TC61/SC11 Plastics Products and relevant
terms applied in the area of welding (including solvent welding) and thermal staking.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
When a term has one or more synonyms, they follow the preferred term. The synonyms are listed in
alphabetical order. Deprecated terms are indicated by “DEPRECATED”.
Some definitions in this International Standard begin with information in angled brackets. This has been
added to indicate limitation of the definition to a particular field.
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 Terms related to welding processes
3.1.1 General terms
3.1.1.1
joining, noun
assembling, noun
DEPRECATED: jointing
process of connecting materials
Note 1 to entry: Includes welding (3.1.1.9), adhesive bonding and mechanical joining.
3.1.1.2
manual welding, noun
welding (3.1.1.9) in which the welding device is manipulated by hand
[1]
[SOURCE: ISO/TR 25901-1:2016 , 2.1.1.8, modified - “electrode holder, gun, torch or blowpipe” in the
definition has been replaced by “welding device”.]

ISO/DIS 472-3:2026(en)
3.1.1.3
semi-automatic welding, noun
process performed manually with equipment controlling one or more of the process parameters
[2]
[SOURCE: AWS A3.0M/A3.0:2020 , modified - “An operation” in the definition for semiautomatic process
has been replaced by “process” and “conditions” has been replaced by “parameters”.]
3.1.1.4
staking, noun
process of melting and reforming a plastic stud to mechanically lock a dissimilar material in place
Note 1 to entry: Includes heat staking - hot air, heat staking - electrical, heat staking – infrared, ultrasonic staking.
[3]
[SOURCE: AWS G1.1M/G1.1:2006 , modified - Note 1 to entry has been added.]
3.1.1.5
swaging, noun
process of capturing another part of an assembly by melting and reforming a ridge of plastic
[3]
[SOURCE: AWS G1.1M/G1.1:2006 ]
3.1.1.6
thermal joining, noun
processes in which the thermoplastic parts to be joined are melted by the application of heat and, after
joining (3.1.1.1) and cooling, form a solid joint
3.1.1.7
weld, noun
result of welding (3.1.1.9)
[1]
[SOURCE: ISO/TR 25901-1:2016 , 2.1.1.3, modified - Note 1 to entry has been removed.]
3.1.1.8
welder, noun
person making a welded assembly by any manual welding (3.1.1.2) process
Note 1 to entry: The manual skill and knowledge of the welder are two of the determining factors influencing the
quality of the welded joint.
[4]
[SOURCE: EN 13067:2020 , 3.18, modified - “or person performing a welding operation by means of
mechanical or automatic equipment” in the definition has been removed and “any process” has been replaced
by “any manual welding process”.]
3.1.1.9
welding, noun
process of uniting softened surfaces of materials, generally with the aid of heat
[5]
[SOURCE: ISO 472:2013/Amd 1:2018 , 2.1252, modified – Note 1 to entry deleted.]
3.1.1.10
welding process, noun
technique characterized by the method of softening to obtain permanent assembly
[4]
[SOURCE: EN 13067:2020 , 3.15]
3.1.2 Welding processes
3.1.2.1
angular vibration welding, noun
angular welding, noun
vibration welding (3.1.2.53) process which uses reciprocating rotational movements to create heating and
melting at surfaces in contact under pressure

ISO/DIS 472-3:2026(en)
3.1.2.2
contour laser welding, noun
transmission laser welding (3.1.2.47) process where the laser beam is guided sequentially along a
predetermined weld (3.1.1.7) path and the laser beam moves along the path just once
3.1.2.3
diffusion welding, noun
DEPRECATED: diffusion bonding
welding process (3.1.1.10) whereby the workpieces are kept in contact under specified continual pressure
and are heated in their entirety at a defined temperature over a controlled time
Note 1 to entry: The molecules from two polymer surfaces under pressure intermingle over time with no, or very
little, deformation.
Note 2 to entry: Welding (3.1.1.9) is carried out at a temperature below the melting point of semi-crystalline polymers
or below the glass transition temperature of amorphous polymers.
[6]
[SOURCE: ISO/TR 25901-3:2016 , 2.2.1.8.1, modified - “welding with pressure” in the definition has been
replaced by “welding process” and Notes to entry have been replaced.]
3.1.2.4
direct drive spin welding, noun
servo-drive spin welding, noun
spin welding (3.1.2.46) using constant speed rotation
[6]
[SOURCE: ISO/TR 25901-3:2016 , 2.2.1.6.4, modified - “friction” in the definition for “direct drive friction
welding” has been replaced by “spin”.]
3.1.2.5
direct laser welding, noun
laser welding process where both parts are opaque to the laser energy and heating is from the laser contact
surface(s)
3.1.2.6
electrofusion saddle welding, noun
electrofusion welding (3.1.2.8) process between an electrofusion saddle fitting (3.1.8.4) and a pipe
3.1.2.7
electrofusion socket welding, noun
electrofusion welding (3.1.2.8) process between an electrofusion socket fitting (3.1.8.5) and a pipe or fitting
with spigotted ends
3.1.2.8
electrofusion welding, noun
EF welding, noun
resistive implant welding (3.1.2.39) process for joining (3.1.1.1) thermoplastic pipes, in which softening of
fitting and pipe surfaces to be welded is obtained by means of a heating element embedded in the fitting,
which remains in the joint
Note 1 to entry: Includes electrofusion socket welding (3.1.2.7) and electrofusion saddle welding (3.1.2.6).
[4]
[SOURCE: EN 13067:2020 , 3.15.1, modified - “resistive implant welding process for joining thermoplastic
pipes, in which” has been added to the definition and “which remain between welded joint” has been replaced
by “which remains in the joint”.]

ISO/DIS 472-3:2026(en)
3.1.2.9
extrusion welding, noun
hot gas extrusion welding, noun
hot gas welding (3.1.2.24) process in which a molten extrudate (3.1.8.6) is extruded into a preheated weld
(3.1.1.7) groove
[2]
[SOURCE: AWS A3.0M/A3.0:2020 , modified - “A welding process” in the definition has been replaced by
“hot gas welding process”.]
3.1.2.10
flash-free welding, noun
welding (3.1.1.9) techniques for pipes, sheets and rods that do not generate any flash (3.1.3.1) and the melt is
fully constrained within the weld (3.1.1.7)
[7]
[SOURCE: ]
3.1.2.11
flow fusion welding, noun
beadless welding, noun
flash-free welding (3.1.2.10) process for joining (3.1.1.1) butting ends of workpieces using a band(s) placed
across the joint to heat the constrained weld (3.1.1.7) zone
[2]
[SOURCE: AWS A3.0M/A3.0:2020 , modified - “A welding process” in the definition has been replaced by
“flash-free welding process”.]
3.1.2.12
FSW, noun
friction stir welding, noun
friction welding (3.1.2.13) process producing a weld (3.1.1.7) by the frictional heating and mixing of material
in the molten or plastic state caused by a rotating tool or vibrating blade that traverses along the weld
(3.1.1.7)
Note 1 to entry: Includes viblade welding (3.1.2.52).
[6]
[SOURCE: ISO/TR 25901-3:2016 , 2.2.1.6.9, modified - “joining” in the definition has been replaced by
“friction welding”, “plastic state” has been replaced by “molten or plastic state”, “rotating tool” has been
replaced by “rotating tool or vibrating blade” and Note 1 to entry has been replaced.]
3.1.2.13
friction welding, noun
welding processes (3.1.1.10) in which the surfaces to be united are softened by heat generated by friction
Note 1 to entry: Includes spin welding (3.1.2.46), ultrasonic welding (3.1.2.51), vibration welding (3.1.2.53), orbital
welding (3.1.2.35), angular vibration welding (3.1.2.1) and friction stir welding (3.1.2.12).
[5]
[SOURCE: ISO 472:2013/Amd 1:2018 , 2.421, modified – “spin welding” has been deleted as an admitted
term, “pressure-welding process” in the definition has been replaced by “welding processes” and Note 1 to
entry has been added.]
3.1.2.14
heated tool welding, noun
welding processes (3.1.1.10) in which the joint surfaces are adequately heated by exposure, through direct
contact with heated elements and are welded under pressure
Note 1 to entry: Includes hot plate welding (3.1.2.25), socket fusion welding (3.1.2.43), saddle fusion welding (3.1.2.40)
and heated wedge welding (3.1.2.15).
[4]
[SOURCE: EN 13067:2020 , 3.15.3, modified - “which includes butt fusion welding (also called hot plate
welding, platen welding or mirror welding) and socket fusion welding” in the definition has been replaced
by Note 1 to entry.]
ISO/DIS 472-3:2026(en)
3.1.2.15
heated wedge welding, noun
hot wedge welding, noun
hot wedge seaming, noun
heated tool wedge welding, noun
hot shoe welding, noun
DEPRECATED: fusion welding
heated tool welding (3.1.2.14) process in which the lining membrane welded is gripped by rollers which
guide and propel the welding (3.1.1.9) machine which uses either hot gas to heat the lining membrane and
the wedge to effect the weld (3.1.1.7) or electrically heated wedge to heat the lining membrane in the area
being welded
[4]
[SOURCE: EN 13067:2020 , 3.15.4]
3.1.2.16
heat sealing, noun
welding processes (3.1.1.10) for joining (3.1.1.1) two or more thin layers of material, at least one of which is a
thermoplastic film, by the simultaneous application of heat and pressure to the areas to be joined
Note 1 to entry: Includes hot bar welding (3.1.2.18), impulse welding (3.1.2.27) and hot air seam welding (3.1.2.17).
[5]
[SOURCE: ISO 472:2013/Amd 1:2018 , 2.458, modified - “process of bonding” in the definition has been
replaced by “welding processes”, “heating areas in contact with each other to the temperature at which fusion
of the thermoplastic film(s) occurs, the bonding usually being completed by the application of pressure” has
been replaced by “the simultaneous application of heat and pressure to the areas to be joined” and Note 1 to
entry has been added.]
3.1.2.17
hot air seam welding, noun
hot air seaming, noun
heat sealing (3.1.2.16) process where high temperature air or gas is introduced between two films or sheets
to facilitate localized surface melting
Note 1 to entry: Pressure is applied to the top or bottom sheet, forcing together the two surfaces to form a continuous
weld (3.1.1.7).
[8]
[SOURCE: GR I - GM19: 20 02 , modified – definition has been revised.]
3.1.2.18
hot bar welding, noun
hot bar sealing, noun
heat sealing (3.1.2.16) process where a heated metal bar is pressed against the films to be welded
[7]
[SOURCE: , modified - “method for joining thermoplastic films and thin sheets” in the definition has been
replaced by “heat sealing process”.]
3.1.2.19
hot gas convection welding, noun
hot gas welding (3.1.2.24) process where the parts to be joined are heated using either a hot inert gas or
exhaust gases from combustion of natural gas
3.1.2.20
hot gas manual welding without welding rod, noun
hot gas welding (3.1.2.24) process where a hot gas torch (3.3.21) fitted with a fish-tail nozzle (3.3.15) is used
to weld (3.1.1.7) lining membranes by blowing hot air between the parts and applying a pressure using a
hand-held roller
ISO/DIS 472-3:2026(en)
3.1.2.21
hot gas round nozzle welding, noun
round nozzle welding, noun
hot gas hand welding, noun
hot gas pendulum welding, noun
fan welding, noun
freehand welding, noun
hot gas welding (3.1.2.24) process where the weld rod (3.1.8.14) is fed into the joint without the aid of a nozzle
(3.3.25); the pressure is applied directly to the weld rod (3.1.8.14) by the welder (3.1.1.8)
[9]
[SOURCE: AWS G1.10M:2016 , modified - “method” in the definition has been replaced by “process”,
“welding nozzle” has been replaced by “nozzle” and “welding rod” has been replaced by “weld rod”.]
3.1.2.22
hot gas speed welding, noun
speed welding, noun
hot gas high-speed welding, noun
high-speed nozzle welding, noun
hot gas welding (3.1.2.24) process in which the weld rod (3.1.8.14) is suitably guided and pre-heated and the
nozzle (3.3.25) tip is provided with a profiled area to apply the welding pressure
[4]
[SOURCE: EN 13067:2020 , 3.15.5 modified - “welding process” in the definition has been replaced by “hot
gas welding process” and “welding rod” has been replaced by “weld rod”.]
3.1.2.23
hot gas wedge welding, noun
hot air wedge welding, noun
welding process (3.1.1.10) for lining membranes in an overlap configuration where a wedge positioned
between the two membranes is heated by hot gas
Note 1 to entry: The lining membranes are gripped by rollers, which provide the welding pressure and also propel the
welding (3.1.1.9) machine along the joint.
3.1.2.24
hot gas welding, noun
hot air welding, noun
DEPRECATED: hot-gas welding
welding processes (3.1.1.10) in which the materials to be welded are softened by hot air or inert gas and are
pressed together
Note 1 to entry: Includes hot gas round nozzle welding (3.1.2.21), hot gas speed welding (3.1.2.22), hot air seam welding
(3.1.2.17), hot gas manual welding without welding rod (3.1.2.20).
[4]
[SOURCE: EN 13067:2020 , 3.15.6, modified - “welding process” in the definition has been replaced by
“welding processes”, “unified” has been replaced by “welded”, and Note 1 to entry has been added.]
3.1.2.25
hot plate welding, noun
butt fusion welding, noun
mirror welding, noun
platen welding, noun
heated tool butt welding, noun
heated tool welding (3.1.2.14) process where the parts to be joined are heated through direct contact with a
hot plate
Note 1 to entry: The hot plate welding cycle is shown in Figure 1 .

ISO/DIS 472-3:2026(en)
Key
S interface stress
S interface bead-up stress
S interface heat-soak stress
S interface fusion/cooling stress
t time
t bead-up time
t heat soak time
t changeover time
t joining pressure build-up time
t fusion/cooling time
Figure 1 — Hot plate welding cycle
3.1.2.26
implant welding, noun
welding processes (3.1.1.10) that require a consumable material at the joint interface (3.1.3.5) that is different
from the parent material as the heat source
Note 1 to entry: Includes resistive implant welding (3.1.2.39), induction welding (3.1.2.28) and microwave welding
(3.1.2.33).
3.1.2.27
impulse welding, noun
impulse sealing, noun
thermal-impulse sealing, noun
heat sealing (3.1.2.16) process in which films are subjected to non-continuous rapid heating under pressure,
pressure being maintained after heating
[5]
[SOURCE: ISO 472:2013/Amd 1:2018 , 2.483, modified - “bonding process” in the definition for “impulse
sealing” has been replaced by “heat sealing process” and “the surfaces to be united” has been replaced by
“films”.]
3.1.2.28
induction welding, noun
welding process (3.1.1.10) where high frequency electromagnetic energy is used to excite molecules of a
ferromagnetic material placed at the joint interface (3.1.3.5)
Note 1 to entry: The heat generated melts the surrounding thermoplastic material, welding (3.1.1.9) the two together.
[7]
[SOURCE: ]
ISO/DIS 472-3:2026(en)
3.1.2.29
inertia spin welding, noun
spin welding (3.1.2.46) process where the rotational energy is stored in a fly wheel; thus the rotational speed
decreases continuously
[6]
[SOURCE: ISO/TR 25901-3:2016 , 2.2.1.6.5, modified – “friction” in the definition for “inertia friction
welding” has been replaced by “spin” and Note 1 to entry has been deleted.]
3.1.2.30
infrared lamp welding, noun
infrared welding (3.1.2.31) process where the heat source is an infrared lamp
Note 1 to entry: Infrared lamps typically radiate at wavelengths between 1 and 3 μm.
3.1.2.31
IR welding, noun
infrared welding, noun
welding (3.1.1.9) techniques where the weld energy (3.4.49) is achieved by infrared radiation
Note 1 to entry: Infrared emitters (3.3.12) include lamps, foils and diodes.
Note 2 to entry: Includes non-contact hot plate welding (3.1.2.34) and infrared lamp welding (3.1.2.30).
Note 3 to entry: The heating phase of the process can be either single-stage or two-stage. Two-stage heating is
performed when welding (3.1.1.9) some polymers in order to achieve the required melt depth to prevent a cold fusion
(3.1.4.5) without degrading the material on the part surface.
[6]
[SOURCE: ISO/TR 25901-3:2016 , 2.2.2.5.10, modified - “light radiation welding” in the definition has been
replaced by “welding techniques” and Notes to entry have been added.]
3.1.2.32
injection welding, noun
variant of extrusion welding (3.1.2.9) where molten thermoplastic is injected into the joint, rather than
extruded
[7]
[SOURCE: ]
3.1.2.33
microwave welding, noun
welding process (3.1.1.10) in which high frequency electromagnetic radiation, usually 2-10GHz, is used to
heat a susceptor material placed at the joint interface (3.1.3.5)
Note 1 to entry: Heat conduction from the susceptor to the joint interface (3.1.3.5) melts the parts and forms a weld
(3.1.1.7).
[7]
[SOURCE: , modified - “A welding technique” in the definition has been replaced by “welding process”.]
3.1.2.34
non-contact hot plate welding, noun
non-contact heated tool butt welding, noun
infrared welding (3.1.2.31) process in which the parts are placed very near a heated tool but are not in direct
contact with it
Note 1 to entry: Heat is transferred to the part surfaces by radiation and convection. The heated tool is removed when
melting occurs and the parts are pressed together to form the welded joint.
[7]
[SOURCE: ]
ISO/DIS 472-3:2026(en)
3.1.2.35
orbital welding, noun
orbital vibration welding, noun
friction welding (3.1.2.13) process which uses repeating rotation of each point on the surface of one part
around a different point on the surface of the other, stationary, part to create heating and melting at the
surfaces in contact
[7]
[SOURCE: , modified - “Process” in the definition has been replaced by “friction welding process” and
“surfaces in contact and under pressure” has been replaced by “the surfaces in contact”.]
3.1.2.36
PCM, noun
polymer coated material joining, noun
technique for joining (3.1.1.1) thermoplastics to non-thermoplastic materials, which involves pre-coating the
non-thermoplastic material with a layer of thermoplastic
Note 1 to entry: The parts are subsequently joined using a plastics welding (3.1.1.9) technique.
[7]
[SOURCE: , modified - “This technology” in the definition has been replaced by “technique for joining
thermoplastics to non-thermoplastic materials, which” and “The components are then joined by welding the
plastic coatings together” has been replaced by “The parts are subsequently joined”.]
3.1.2.37
quasi-simultaneous laser welding, noun
laser scan welding, noun
transmission laser welding (3.1.2.47) process where the laser beam is guided along the weld (3.1.1.7) profile
at high speed and traverses the weld (3.1.1.7) path multiple times
3.1.2.38
RF welding, noun
radio frequency welding, noun
dielectric welding, noun
high frequency welding, noun
HF welding, noun
welding process (3.1.1.10) using heat produced by polar molecular vibrations induced by radio frequency
emission
[2]
[SOURCE: AWS A3.0M/A3.0:2020 , modified - “A welding process” in the definition has been replaced by
“welding process using heat produced by polar molecular vibrations”.]
3.1.2.39
resistive implant welding, noun
welding process (3.1.1.10) for thermoplastics and composites in which heat is generated by application of an
electric current to a conductive heating element placed at the joint interface (3.1.3.5)
Note 1 to entry: The heating element remains in the joint after welding (3.1.1.9).
Note 2 to entry: Includes electrofusion welding (3.1.2.8).
[7]
[SOURCE: , modified – definition has been revised and Notes to entry added]
3.1.2.40
saddle fusion welding, noun
sidewall fusion welding, noun
variant of heated tool welding (3.1.2.14) of pipes where a joint is made by heating the curved surface of a
saddle and the outside surface of a pipe
Note 1 to entry: The parts are held against a heated tool until the polymer reaches the welding temperature, quickly
removing the heated tool and pushing the two softened surfaces against each other.
[10]
[SOURCE: EN 12201-1:2011 , 3.1.5.3, modified - “joint made” in definition for “saddle fusion joint” has
been replaced by “variant of heated tool welding of pipes where a joint is made”, the rest of the definition has

ISO/DIS 472-3:2026(en)
been moved to Note 1 to entry, “by holding them” has been replaced by “The parts are held”, “PE material”
has been replaced by “polymer” and “fusion temperature” has been replaced by “welding temperature”.]
3.1.2.41
seam welding, noun
group of welding processes (3.1.1.10) for films, membranes and fabrics, in which overlapping portions of the
surfaces to be united are softened by heat or solvent
[5]
[SOURCE: ISO 472:2013/Amd 1:2018 , 2.902, modified - “pressure-welding process” in the definition has
been replaced by “group of welding processes for films, membranes and fabrics”.]
3.1.2.42
simultaneous laser welding, noun
laser welding process where one or more laser beams heat the entire weld (3.1.1.7) interface at the same
time
3.1.2.43
socket fusion welding, noun
heated tool welding (3.1.2.14) process for thermoplastic pipes where a joint is made by melting together the
outer part of the pipe with the inner part of a fitting by means of heat from a heated tool
Note 1 to entry: After a preset time, the pipe and fitting are removed from the tool and the pipe is inserted into the
fitting and held until the joint cools.
Note 2 to entry: See Figure 2 below.
Key
1 socket fitting
2 heated socket fusion tool
3 pipe
Figure 2 — Socket fusion welding - Pipe and fitting on heated tool

ISO/DIS 472-3:2026(en)
[11]
[SOURCE: ISO 22391-3:2009 , 3.3.1, modified - “fitting in which the joint with the pipe” in the definition
for “socket fusion fitting” has been replaced by “heated tool welding process for thermoplastic pipes where a
joint” and Note 1 to entry has been added.]
3.1.2.44
solvent cement welding, noun
solvent cementing, noun
solvent welding (3.1.2.45) process for joining (3.1.1.1) thermoplastics by applying a solution of a solvent
capable of softening the surfaces to be welded and the same plastic as the parent material, by pressing the
softened surfaces together and allowing the solvent to evaporate
3.1.2.45
solvent welding, noun
solvent fusion, noun
DEPRECATED: solvent bonding
welding process (3.1.1.10) for thermoplastics by applying a solvent capable of softening the surfaces to be
welded, pressing the softened surfaces together, and removing the solvent by evaporation
Note 1 to entry: Includes solvent cement welding (3.1.2.44).
[5]
[SOURCE: ISO 472:2013/Amd 1:2018 , 2.962, modified - “process of bonding” in the definition of “solvent
bonding” has been replaced by “welding process for”, “united” has been replaced by “welded” and Note 1 to
entry has been added.]
3.1.2.46
spin welding, noun
rotational welding, noun
friction welding (3.1.2.13) process for joining (3.1.1.1) thermoplastic parts with a circular joint line
Note 1 to entry: Frictional heat develops as one part spins against the other, resulting in melting at the joint interface
(3.1.3.5).
Note 2 to entry: Includes direct drive spin welding (3.1.2.4) and inertia spin welding (3.1.2.29).
Note 3 to entry: The equivalent to friction welding for metallic materials.
[7]
[SOURCE: , modified - “A method used” in the definition has been replaced by “friction welding process”,
“the other, stationary part, resulting” has been replaced by “the other, resulting” and “Spinning is then
stopped, and the parts are held together under pressure until cool” has been deleted.]
3.1.2.47
transmission laser welding, noun
through-transmission laser welding, noun
laser welding process where heat is generated at the interface of a laser-transparent part and a laser-
absorbing part
Note 1 to entry: The laser beam passes through the laser-transparent part and the laser energy is absorbed by the
laser-absorbing part to produce a weld (3.1.1.7).
Note 2 to entry: Includes contour laser welding (3.1.2.2), simultaneous laser welding (3.1.2.42) and quasi-simultaneous
laser welding (3.1.2.37).
3.1.2.48
ultrasonic sewing, noun
ultrasonic welding (3.1.2.51) process for the joining (3.1.1.1) of thermoplastic fabrics by passing the materials
between an ultrasonic horn (3.3.19) and a patterned stitching anvil (3.3.3) wheel
[3]
[SOURCE: AWS G1.1M/G1.1:2006 ]

ISO/DIS 472-3:2026(en)
3.1.2.49
ultrasonic spot welding, noun
ultrasonic welding (3.1.2.51) process for joining (3.1.1.1) two thermoplastic parts or sheets at localized points
with no preformed hole or energy director (3.1.6.1)
[3]
[SOURCE: AWS G1.1M/G1.1:2006 , modified, “components” in the definition have been replaced by “parts”.]
3.1.2.50
ultrasonic swaging, noun
joining (3.1.1.1) process in which ultrasonic energy is used to form a ring or ridge of plastic in one of the
mating parts in order to capture the other part
[7]
[SOURCE: , modified - “An assembly method” in the definition has been replaced by “joining process”.]
3.1.2.51
ultrasonic welding, noun
friction welding (3.1.2.13) process in which mechanical vibrations of high frequencies and of low amplitude
(3.4.1), superimposed on a static force, make a weld (3.1.1.7) between the two parts to be joined
Note 1 to entry: Parts may require the use of an energy director (3.1.6.1) in order to concentrate the ultrasonic energy.
[6]
[SOURCE: ISO/TR 25901-3:2016 , 2.2.1.6.1, modified - “welding with pressure” in the definition has been
replaced by “friction welding process”, “workpieces” has been replaced by “parts”, “at a temperature well
below the melting point of the material” has been deleted and Note 1 to entry has been revised.]
3.1.2.52
viblade welding, noun
variant of friction stir welding (3.1.2.12) for joining (3.1.1.1) thermoplastic sheets, where the heat is generated
by a vibrating metal blade that traverses along the joint
Note 1 to entry: See Figure 3 below.

ISO/DIS 472-3:2026(en)
Key
1 blade
2 shoulder
3 thermoplastic sheets
4 welding direction
5 vibration direction
6 vertical load
Figure 3 — Schematic of viblade welding
[7]
[SOURCE: , modified – a figure has been added.]
3.1.2.53
vibration welding, noun
linear vibration welding, noun
linear friction welding, noun
friction welding (3.1.2.13) process in which frictional heat is generated by rubbing the two parts together in
a linear reciprocating motion
Note 1 to entry: The vibratory frequency is typically 120-240 Hz and the amplitude (3.4.1) is typically 0,7 - 4,0 mm.
Note 2 to entry: Includes vibration welding with IR preheat (3.1.2.54).
[7]
[SOURCE: , modified - “linear or angular motion” in the definition has been replaced by “linear
reciprocating motion”, “When the generated heat melts the two materials at the joint interface, vibration is
terminated, and the parts are pressed together and allowed to cool” and “ Vibration welding produces high
strength bonds and is particularly suited to large parts” have been deleted and a Note 1 to entry has been
added.]
3.1.2.54
vibration welding with IR preheat, noun
vibration welding (3.1.2.53) process where the surfaces to be welded are heated using infrared radiation
before being brought together for the vibration stage
Note 1 to entry: This reduces the formation of particulates during the welding process (3.1.1.10).

ISO/DIS 472-3:2026(en)
3.1.3 Characterization of welds
3.1.3.1
flash, noun
upset, noun
material displaced from the joint area as a result of welding (3.1.1.9)
[12]
[SOURCE: AWS G1.2M/G1.2:1999 ]
3.1.3.2
HAZ, noun
heat affected zone, noun
portion of non-melted parent material whose microstructure has been affected
[1]
[SOURCE: ISO/TR 25901-1:2016 , 2.1.2.2, modified - “metal” in the definition has been replaced by
“material”.]
3.1.3.3
hermetic seal, noun
weld (3.1.1.7) able to withstand positive pressure or negative pressure (vacuum) without leaking
[3]
[SOURCE: AWS G1.1M/G1.1:2006 ]
3.1.3.4
insertion depth, noun
penetration depth, noun
distance the pipe is inserted into the
socket fitting
3.1.3.5
joint interface, noun
contact surface of two mating parts
[3]
[SOURCE: AWS G1.1M/G1.1:2006 , modified - “weld” in the definition has been deleted.]
3.1.3.6
melt indicator, noun
DEPRECATED: weld indicator
feature on an electrofusion socket fitting (3.1.8.5) or electrofusion saddle fitting
(3.1.8.4) that uses the expansion of the molten pool produced in the melt zone (3.1.3.7) during the welding
(3.1.1.9) cycle to push a plastic pin radially outwards from a hole in the fitting
Note 1 to entry: The melt indicator informs the operator that melt pressure has developed.
3.1.3.7
fusion zone, noun
melt zone, noun
region containing the weld (3.1.1.7) interface and having a boundary line reflecting the limits of crystalline
melting
3.1.3.8
solvent affected zone, noun
SAZ, noun
depth either side of the joint that the solvent diffuses into the thermoplastic
[7]
[SOURCE: ]
3.1.3.9
weld bead, noun
upset material, noun
molten material squeezed out of the weld (3.1.1.7)

ISO/DIS 472-3:2026(en)
3.1.3.10
weld face, noun
exposed surface of a weld (3.1.1.7) on the side from which the
welding (3.1.1.9) was done
[2]
[SOURCE: AWS A3.0M/A3.0:2020 , modified - “The exposed” in the definition has been replaced by
“exposed” and “See Figures B24(A) and B24(E)” has been deleted.]
3.1.4 Imperfections
3.1.4.1
angular misalignment, noun
deviation from specified angle between two welded pieces
[13]
[SOURCE: EN 14728:2019 ]
3.1.4.2
bead start/stop crack, noun
crack occurring at the start/stop of a weld (3.1.1.7) due to the thermal
characteristics of an overstressed weld rod (3.1.8.14)
Note 1 to entry: See Figure 4 below.

ISO/DIS 472-3:2026(en)
a) Parallel crack
b) Perpendicular crack
ISO/DIS 472-3:2026(en)
c) Radiating crack
Figure 4 — Schematic of bead start/stop crack
[9]
[SOURCE: AWS G1.10M:2016 ]
3.1.4.3
burn through, noun
local collapse of weld bead (3.1.3.9) in the root pass
[13]
[SOURCE: EN 14728:2019 , modified - “(root pass)” in the definition has been replaced by “in the root
pass”.]
3.1.4.4
burn through, noun
weld run (3.1.7.22) that penetrates the lower membrane of an overlap weld
[13]
[SOURCE
...