EN ISO 5179:2023

Investigation of brazeability with spreading and gap-filling test (ISO 5179:2021)

This document specifies three test methods for investigating brazeability.
A spreading test shows testing method with measurement of the spread area of the filler metals.
A T-joint test describes a scheme to construct a T-shape design by the test pieces and a testing method.
A varying gap test describes a test piece and a testing method for assessing the influence of the various parameters which can influence brazing during manufacture as a function of clearances.

Untersuchung der Hartlötbarkeit mithilfe der Verteilungs- und der Spaltfüllprüfung (ISO 5179:2021)

Dieses Dokument legt drei Prüfverfahren zur Untersuchung der Hartlötbarkeit fest.
Eine Verteilungsprüfung ist ein Prüfverfahren, bei dem die Ausbreitungsfläche des Hartlotes gemessen wird.
Eine T Fugen-Prüfung beschreibt ein Schema, um eine T Form durch Prüfproben herzustellen, und ein Prüfverfahren.
Ein Prüfverfahren mit wechselnder Spaltbreite beschreibt eine Prüfprobe und ein Prüfverfahren, um den Einfluss der unterschiedlichen Parameter, die das Hartlöten während der Fertigung beeinflussen können, als Funktion von Abständen zu untersuchen.

Étude de l'aptitude au brasage au moyen d'un essai de mouillage et de capillarité (ISO 5179:2021)

Le présent document spécifie trois méthodes d'essai pour étudier l'aptitude au brasage fort.
Un essai de mouillage présente une méthode d'essai avec mesure de la zone de mouillage des métaux d'apport.
Un essai avec un assemblage en T décrit un schéma de conception et une méthode d'essai pour des éprouvettes en T.
Un essai avec éprouvette à jeu variable décrit une éprouvette et une méthode d’essai pour évaluer l’influence des différents paramètres qui peuvent agir sur le brasage fort lors de son exécution en fonction des jeux.

Preskus spajkalnosti z omočljivostjo in s kapilarnostjo v ozki reži (ISO 5179:2021)

Ta dokument določa tri preskusne metode za preskušanje spajkalnosti.
Preskus omočljivosti prikazuje preskusno metodo z merjenjem območja omočljivosti dodajnih materialov.
Preskus T-spoja opisuje shemo za izdelavo zasnove v obliki črke T iz preskušancev in preskusno metodo. Preskus variabilne vrzeli opisuje preskušanec in preskusno metodo za ocenjevanje vpliva različnih parametrov na spajkanje med izdelavo kot funkcijo odmikov.

General Information

• Status: Published
• Publication Date: 09-May-2023
• ICS: 25.160.50 - Brazing and soldering
• Technical Committee: CEN/TC 121 - Welding
• Drafting Committee: CEN/TC 121 - Welding
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 10-May-2023
• Due Date: 17-Jan-2025
• Completion Date: 10-May-2023
• Ref Project: SIST EN ISO 5179:2023 - Investigation of brazeability with spreading and gap-filling test (ISO 5179:2021)

Overview

EN ISO 5179:2023 (adoption of ISO 5179:2021 by CEN) defines standardized methods to investigate brazeability using spreading and gap-filling tests. The document specifies three complementary test methods-spreading test, T‑joint test, and varying gap test-to assess how a brazing filler metal wets and flows into joints (wettability and capillarity). The standard is intended for use in laboratories and industry to evaluate filler metal behavior under controlled conditions and to support process design, quality control and material selection.

Key topics and requirements

• Three test methods
  • Spreading test: measures the spread area of a filler metal on a plate to evaluate wettability. Typical test-piece dimensions are given (plate thickness (2.0 ± 1.0) mm; width/length (40 ± 10) mm) and a filler metal charge (~10 mm).
  • T‑joint test: constructs a T-shaped assembly to evaluate gap filling in a practical joint geometry. Plate dimensions, spacer rod specification (diameter (0.50 ± 0.01) mm) and filler metal placement are specified.
  • Varying gap test: uses concentric tube geometry to assess capillary filling across gaps from 0 mm to 0.5 mm; dimensional tolerances for outer/inner tubes and root face bevel are provided.
• Test setup and preparation: instructions for specimen preparation, flux application (when required), and filler metal mass conversion from volume using density.
• Brazing cycle and examination: the standard covers brazing cycle control, visual and micrographic examination (including microsection inspection for varying gap test), and criteria for recording results.
• Results and reporting: procedures for documenting spread area, gap filling performance and micrographic findings to characterize overall brazeability (wettability + fluidity).

Applications and users

• Who uses it: materials engineers, brazing/welding specialists, quality/control laboratories, R&D teams in aerospace, automotive, HVAC, electronics and manufacturing sectors that rely on brazed joints.
• Practical uses:
  • Comparing filler metals or fluxes for a given parent material.
  • Developing brazing processes and joint clearances for reliable capillary flow.
  • Verifying supplier claims and supporting failure analysis or qualification testing.

Related standards

• ISO 857‑2 (vocabulary for soldering and brazing processes) is referenced normatively in EN ISO 5179:2023.
• EN ISO 5179:2023 is the CEN-endorsed version of ISO 5179:2021 (no technical modifications).

Keywords: EN ISO 5179:2023, brazeability, spreading test, T‑joint test, varying gap test, gap-filling test, brazing, wettability, capillarity, brazing test methods.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2023
Preskus spajkalnosti z omočljivostjo in s kapilarnostjo v ozki reži (ISO 5179:2021)
Investigation of brazeability with spreading and gap-filling test (ISO 5179:2021)
Untersuchung der Hartlötbarkeit anhand der Verteilung und mittels des
Spaltfüllverfahrens (ISO 5179:2021)
Étude de l'aptitude au brasage au moyen d'un essai de mouillage et de capillarité (ISO
5179:2021)
Ta slovenski standard je istoveten z: EN ISO 5179:2023
ICS:
25.160.50 Trdo in mehko lotanje Brazing and soldering
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 5179
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2023
EUROPÄISCHE NORM
ICS 25.160.50
English Version
Investigation of brazeability with spreading and gap-filling
test (ISO 5179:2021)
Étude de l'aptitude au brasage au moyen d'un essai de Untersuchung der Hartlötbarkeit anhand der
mouillage et de capillarité (ISO 5179:2021) Verteilung und mittels der Spaltfüllprüfung (ISO
5179:2021)
This European Standard was approved by CEN on 7 May 2023.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 5179:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 5179:2021 has been prepared by Technical Committee ISO/TC 44 "Welding and allied
processes” of the International Organization for Standardization (ISO) and has been taken over as
of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2023, and conflicting national standards
shall be withdrawn at the latest by November 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 5179:2021 has been approved by CEN as EN ISO 5179:2023 without any modification.

INTERNATIONAL ISO
STANDARD 5179
Second edition
2021-03
Investigation of brazeability with
spreading and gap-filling test
Étude de l'aptitude au brasage au moyen d'un essai de mouillage et
de capillarité
Reference number
ISO 5179:2021(E)
©
ISO 2021
ISO 5179:2021(E)
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

ISO 5179:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Description of the test piece . 1
4.1 Spreading test piece. 1
4.2 Gap filling test . 2
4.2.1 T-joint test piece . 2
4.2.2 Varying gap test piece . 2
5 Purpose of the test . 3
6 Preparation of test piece . 3
7 Brazing cycle . 3
8 Examination . 4
8.1 Spreading test piece. 4
8.2 T-joint test piece . . 4
8.3 Varying gap test piece . 4
9 Micrographic inspection for varying gap test. 4
9.1 Varying gap test piece . 4
10 Results . 4
Bibliography .12
ISO 5179:2021(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 44, Welding and allied processes,
Subcommittee SC 13, Brazing materials and processes.
This second edition cancels and replaces the first edition (ISO 5179:1983), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— the spreading test has been added;
— the T-joint test has been added.
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 https:// www .iso .org/ members .html.
Official interpretations of ISO/TC 44 documents, where they exist, are available from this page: https://
committee .iso .org/ sites/ tc44/ home/ interpretation .html.
iv © ISO 2021 – All rights reserved

ISO 5179:2021(E)
Introduction
When designing and making a brazed joint, quite apart from the physical properties of the brazing
alloy and the mechanical properties which can be expected from the joint, it is important to know
the brazeability as a function of the operating conditions adop
...