CEN/TC 121/WG 20 - Brazing

This document specifies the compositional ranges of a series of filler metals used for brazing. The filler metals are divided into seven classes, related to their composition but not necessarily to the major element present.
NOTE 1        For the major element(s) present, see Annex A.
In the case of composite products, such as flux-coated rods, pastes or plastics tapes, this document covers only the filler metal that forms parts of such products. The melting temperatures given in the tables are only approximate, as they necessarily vary within the compositional range of the filler metal. Therefore, they are given only for information. Technical delivery conditions are given for brazing filler metals and products containing brazing filler metals with other constituents such as flux and/or binders.
NOTE 2        For some applications, such as precious metal jewellery, aerospace and dental, filler metals other than those included in this document are often used. These are covered by other International Standards to which reference can be made.

This document gives guidance on the application of brazing and the manufacture of brazed joints. This standard gives an introduction to brazing and a basis for the understanding and use of brazing in different applications. Because of the wide range of applications of brazing this standard does not give detailed guidance that might be product specific. For such information reference should be made to the appropriate product standard or, for applications where this does not exist, the relevant criteria should be clearly established before any brazing is undertaken.
This standard covers joint design and assembly, material aspects for both parent material and filler materials, brazing process and process variables, pre- and post-braze treatment and inspection.

This European Standard describes destructive test procedures and test piece types necessary to perform the tests on brazed joints.
Brazed joints are used in a wide variety of assemblies and the design requirements placed upon these joints will also vary widely; there will usually be some level of strength required but this may not be explicitly stated and is frequently of minor importance compared to some
other criterion, e.g. hermeticity. It follows that a test which measures strength may be totally irrelevant in assessing a joint for a particular application where strength is a minor consideration. This situation is made more complicated because brazed joints are almost
invariably designed to be loaded in shear and the dimensions of the joint affect the shear strength to a much greater extent than they do the tensile strength. The tests described in this standard have been used successfully to give information on specific properties and where such information is needed, it is recommended that one of them be specified. It is vital to recognise that for many fabrications none of these tests will be suitable and specific tests will have to be devised, which do yield the requisite information (which may be qualitative rather then quantitative). The destructive test methods described are as follows: a) shear tests (see clause 4); b) tensile tests (see clause 5); c) metallographic examination (see clause 6); d) hardness tests (see clause 7); e) peel test (see clause 8); f) bend tests (see clause 9).
Details of burst tests are not included as these are not commonly used on brazed joints. The type of test piece described for each test can be quoted or incorporated in engineering applications standards that deal with brazed assemblies. The results of the tests are used:
1) to determine basic data regarding filler metal performance; 2) to arrive at optimum brazing designs (including gaps) and brazing
procedures...(Truncated)

This European Standard describes non-destructive examination procedures and test piece types necessary to perform the tests on brazed joints. The non-destructive examination methods described are as follows: a) visual examination (see clause 4); b) ultrasonic examination (see clause 5); c) radiographic examination (see clause 6); d) penetrant examination (see clause 7); e) leak testing (see clause 8); f) proof testing (see clause 9); g) thermography (see clause 10). The brazed joints to which these tests are applied can either be test samples manufactured to obtain brazed joint design data, or manufactured as part of the approval testing of a brazing procedure, or parts of a brazed assembly. The type of test piece described for each test can be quoted or incorporated in engineering application standards that deal with brazed assemblies. This European Standard does not recommend the number of samples to be tested or the repeat tests allowed. Neither does it specify methods of sampling brazed joints, except to give guidance regarding the precautions necessary, nor does it comment on the acceptance criteria applicable to any of the tests. No attempt is made to define which test or tests, if any , should be applied in any situation. This is a matter to be established before any particular method of test is selected. The methods of non-destructive examination are not associated with any particular type of brazed assembly but lay down the general principles of the types of testing described. It is emphasised that a satisfactory examination method can only be developed and used after taking into account all the relevant factors regarding the equipment to be used and the characteristics of the test piece being examined.

This European Standard specifies general rules (test procedures, test pieces) for the specification and approval of brazing procedures for all materials, metallic and non-metallic. It is anticipated that, where necessary, specific requirements for individual industries will be developed within this framework and detailed in the relevant application standard. The recommended format for the procedure approval
certificate is given in annex B. It assumes that the brazing procedure specifications are used in production and, in the case of manual flame brazing, by competent brazers approved in accordance with EN 13133, where relevant.

This European Standard describes non-destructive examination procedures and test piece types necessary to perform the tests on brazed joints. The non-destructive examination methods described are as follows: a) visual examination (see clause 4); b) ultrasonic examination (see clause 5); c) radiographic examination (see clause 6); d) penetrant examination (see clause 7); e) leak testing (see clause 8); f) proof testing (see clause 9); g) thermography (see clause 10). The brazed joints to which these tests are applied can either be test samples manufactured to obtain brazed joint design data, or manufactured as part of the approval testing of a brazing procedure, or parts of a brazed assembly. The type of test piece described for each test can be quoted or incorporated in engineering application standards that deal with brazed assemblies. This European Standard does not recommend the number of samples to be tested or the repeat tests allowed. Neither does it specify methods of sampling brazed joints, except to give guidance regarding the precautions necessary, nor does it comment on the acceptance criteria applicable to any of the tests. No attempt is made to define which test or tests, if any , should be applied in any situation. This is a matter to be established before any particular method of test is selected. The methods of non-destructive examination are not associated with any particular type of brazed assembly but lay down the general principles of the types of testing described. It is emphasised that a satisfactory examination method can only be developed and used after taking into account all the relevant factors regarding the equipment to be used and the characteristics of the test piece being examined.

This European Standard describes destructive test procedures and test piece types necessary to perform the tests on brazed joints.
Brazed joints are used in a wide variety of assemblies and the design requirements placed upon these joints will also vary widely; there will usually be some level of strength required but this may not be explicitly stated and is frequently of minor importance compared to some
other criterion, e.g. hermeticity. It follows that a test which measures strength may be totally irrelevant in assessing a joint for a particular application where strength is a minor consideration. This situation is made more complicated because brazed joints are almost
invariably designed to be loaded in shear and the dimensions of the joint affect the shear strength to a much greater extent than they do the tensile strength. The tests described in this standard have been used successfully to give information on specific properties and where such information is needed, it is recommended that one of them be specified. It is vital to recognise that for many fabrications none of these tests will be suitable and specific tests will have to be devised, which do yield the requisite information (which may be qualitative rather then quantitative). The destructive test methods described are as follows: a) shear tests (see clause 4); b) tensile tests (see clause 5); c) metallographic examination (see clause 6); d) hardness tests (see clause 7); e) peel test (see clause 8); f) bend tests (see clause 9).
Details of burst tests are not included as these are not commonly used on brazed joints. The type of test piece described for each test can be quoted or incorporated in engineering applications standards that deal with brazed assemblies. The results of the tests are used:
1) to determine basic data regarding filler metal performance; 2) to arrive at optimum brazing designs (including gaps) and brazing
procedures...(Truncated)

This European Standard describes non-destructive examination procedures and test piece types necessary to perform the tests on brazed joints.
The non-destructive examination methods described are as follows:
a)   visual examination (see Clause 4);
b)   ultrasonic examination (see Clause 5);
c)   radiographic examination (see Clause 6);
d)   penetrant examination (see Clause 7);
e)   leak testing (see Clause 8);
f)   proof testing (see Clause 9);
g)   thermography (see Clause 10).
The brazed joints to which these tests are applied can either be test samples manufactured to obtain brazed joint design data, or manufactured as part of the approval testing of a brazing procedure, or parts of a brazed assembly. The type of test piece described for each test can be quoted or incorporated in engineering application standards that deal with brazed assemblies.
This European Standard does not recommend the number of samples to be tested or the repeat tests allowed. Neither does it specify methods of sampling brazed joints, except to give guidance regarding the precautions necessary, nor does it comment on the acceptance criteria applicable to any of the tests. No attempt is made to define which test or tests, if any, should be applied in any situation. This is a matter to be established before any particular method of test is selected.
The methods of non-destructive examination are not associated with any particular type of brazed assembly but lay down the general principles of the types of testing described. It is emphasized that a satisfactory examination method can only be developed and used after taking into account all the relevant factors regarding the equipment to be used and the characteristics of the test piece being examined.

This European Standard describes destructive test procedures and test piece types necessary to perform the tests on brazed joints.
Brazed joints are used in a wide variety of assemblies and the design requirements placed upon these joints will also vary widely; there will usually be some level of strength required but this may not be explicitly stated and is frequently of minor importance compared to some other criterion, e.g. hermeticity. It follows that a test which measures strength may be totally irrelevant in assessing a joint for a particular application where strength is a minor consideration. This situation is made more complicated because brazed joints are almost invariably designed to be loaded in shear and the dimensions of the joint affect the shear strength to a much greater extent than they do the tensile strength. The tests described in this standard have been used successfully to give information on specific properties and where such information is needed, it is recommended that one of them be specified.
It is vital to recognise that for many fabrications none of these tests will be suitable and specific tests will have to be devised, which do yield the requisite information (which may be qualitative rather than quantitative). The destructive test methods described are as follows:
a)   shear tests (see Clause 4);
b)   tensile tests (see Clause 5);
c)   metallographic examination (see Clause 6);
d)   hardness tests (see Clause 7);
e)   peel test (see Clause 8);
f)   bend tests (see Clause 9).
Details of burst tests are not included as these are not commonly used on brazed joints.
The type of test piece described for each test can be quoted or incorporated in engineering applications standards that deal with brazed assemblies.
The results of the tests are used:
g)   to determine basic data regarding filler metal performance;
h)   to arrive at optimum brazing designs (including gaps) and brazing procedures;
i)   to relate production results to results achieved in development.
This European Standard does not recommend the number of samples to be tested or the repeat tests allowed. Neither does it specify methods of sampling brazed joints, except to give guidance regarding the precautions necessary, nor does it comment on the acceptance criteria applicable to any of  the tests.
No attempt is made to define which test or tests, if any, should be applied in any situation. This is a matter to be established before any particular method of test is selected.

This European Standard gives guidance on the application of brazing and the manufacture of brazed joints. This standard gives an introduction to brazing and a basis for the understanding and use of brazing in different applications. Because of the wide range of applications of brazing, this standard does not give detailed guidance that might be product specific. For such information, reference should be made to the appropriate product standard or, for applications where this does not exist, the relevant criteria should be clearly established before any brazing is undertaken.
This standard covers joint design and assembly, material aspects for both parent material and filler materials, brazing process and process variables, pre- and post-braze treatment and inspection.

This document specifies requirements for qualification testing of brazers and brazing operators for metallic materials.
This document gives general provisions on quality requirements for brazing (see Annex A).
This document applies to the following brazing processes according to ISO 857-2 and ISO 4063:2009 with local and global heating:
—    911 Infrared brazing;
—    912 Flame brazing, torch brazing;
—    913 Laser beam brazing;
—    914 Electron beam brazing;
—    916 Induction brazing;
—    918 Resistance brazing;
—    919 Diffusion brazing;
—    921 Furnace brazing;
—    922 Vacuum brazing;
—    923 Dip-bath brazing;
—    924 Salt-bath brazing;
—    925 Flux bath brazing;
—    926 Immersion brazing;
—    972 Arc weld brazing.
This document is not applicable to personnel operating brazing equipment who do not have any direct influence on the quality of the brazed joint, for example, personnel performing exclusively loading/unloading the brazing unit or just initiating the brazing cycle in automatic brazing.
The principles of this document can be applied to other brazing processes and brazing of materials not listed.
This document does not apply to brazing for aerospace applications covered by ISO 11745.

ISO 13585:2012 specifies basic requirements for the qualification testing of brazers and brazing operators providing conditions for brazing, testing, examination, acceptance criteria and range of qualification for certificates.

ISO 17672:2016 specifies the compositional ranges of a series of filler metals used for brazing. The filler metals are divided into seven classes, related to their composition, but not necessarily to the major element present.

ISO 18279:2003 details a classification of imperfections that can occur in brazing joints. In addition guidance is provided on quality levels and suggested limits for imperfections are detailed.
For requirements not covered by this standard, reference is to be made to other sources, e.g. statutory regulations, codes of practice and technical delivery conditions.
No information is given on how imperfections are to be assessed in individual cases because this depends on the requirements for the particular brazed joint. These imperfections are not always detectable by the use of non-destructive testing alone.
The standard covers only imperfections that can occur in connection with brazing without the effect of any additional service loads. Only the type, shape and position of such imperfections are covered; no indication is given of the conditions of occurrence or causes.
For requirements for brazed joints which are relevant and essential to the particular function of the component, reference should be made to the relevant documentation, e.g. manufacturing documents or procedure sheets.
This International Standard does not lay down requirements for acceptance levels for imperfections since these will differ very markedly, depending on the application, but it does suggest some quality levels which may be of value in the absence of more detailed information.

This standard specifies the classification of fluxes used for brazing metals and characterizes these fluxes on the basis of their properties and use, and gives technical delivery conditions and health and safety precautions.

ISO 17672:2010 specifies the compositional ranges of a series of filler metals used for brazing. The filler metals are divided into seven classes, related to their composition, but not necessarily to the major element present.
In the case of composite products, such as flux-coated rods, pastes or plastics tapes, ISO 17672:2010 covers only the filler metal that forms part of such products.