IEC 63093-6:2018

Ferrite cores - Guidelines on dimensions and the limits of surface irregularities - Part 6: ETD-cores for use in power supplies

IEC 63093-6:2018 specifies the dimensions that are of importance for mechanical interchangeability for a preferred range of ETD-cores made of ferrite and the essential dimensions of coil formers to be used with them, as well the effective parameter values to be used in calculations involving them. It also gives guidelines on allowable limits of surface irregularities applicable to ETD-cores.
The specifications contained in this document are useful in negotiations between ferrite core manufacturers and users about surface irregularities. The use of derived standards which give more detailed specifications of component parts while still permitting compliance with this document is discussed in  REF _Ref506796608 \r \h Annex A 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003500300036003700390036003600300038000000 .
This edition includes the following significant technical changes with respect to IEC 62317-­6:2015 and IEC 60424-3:2015:
a. This document integrates IEC 62317-6:2015 and IEC 60424-3:2015;
b. Table 1 – Allowable areas of chips for ETD-cores, of IEC 60424-3:2015, has been moved to Annex C (informative) of this document.

Noyaux ferrites - Lignes directrices relatives aux dimensions et aux limites des irrégularités de surface - Partie 6: Noyaux ETD utilisés dans les alimentations électriques

L'IEC 63093-6:2018 spécifie les dimensions qui jouent un rôle majeur dans l'interchangeabilité mécanique d'une gamme préférentielle de noyaux ETD constitués de ferrites et les dimensions essentielles des supports de bobine à utiliser avec ces noyaux, ainsi que les valeurs des paramètres effectifs à utiliser dans les calculs qui les impliquent. Elle donne également les lignes directrices relatives aux limites admissibles des irrégularités de surface applicables aux noyaux ETD.
Les spécifications du présent document sont utiles aux négociations entre les fabricants de noyaux ferrites et leurs utilisateurs concernant les irrégularités de surface.
Cette première édition annule et remplace la première édition de l'IEC 62317-6 parue en 2015 et la deuxième édition de l'IEC 60424-3 parue en 2015. Cette édition constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'IEC 62317­6:2015 et à l'IEC 60424-3:2015:  
le présent document intègre l'IEC 62317-6:2015 et l'IEC 60424­3:2015;
le Tableau 1 – Surfaces admissibles des éclats pour les noyaux ETD, de l'IEC 60424‑3:2015, a été déplacé à l'Annexe C (informative) du présent document.

General Information

• Status: Published
• Publication Date: 26-Jun-2018
• ICS: 29.100.10 - Magnetic components
• Technical Committee: TC 51 - Magnetic components, ferrite and magnetic powder materials
• Drafting Committee: WG 1 - TC 51/WG 1
• Current Stage: PPUB - Publication issued
• Start Date: 27-Jun-2018
• Completion Date: 23-Jul-2018

Relations

• Replaces: IEC 60424-3:2015 - Ferrite cores - Guidelines on the limits of surface irregularities - Part 3: ETD-cores, EER-cores, EC-cores and E-cores
• Effective Date: 05-Sep-2023
• Replaces: IEC 62317-6:2015 - Ferrite cores - Dimensions - Part 6: ETD-cores for use in power supplies
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 63093-6 ®
Edition 1.0 2018-06
INTERNATIONAL
STANDARD
Ferrite cores – Guidelines on dimensions and the limits of surface
irregularities –
Part 6: ETD-cores for use in power supplies

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.

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IEC 63093-6 ®
Edition 1.0 2018-06
INTERNATIONAL
STANDARD
Ferrite cores – Guidelines on dimensions and the limits of surface

irregularities –
Part 6: ETD-cores for use in power supplies

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.100.10 ISBN 978-2-8322-5834-7

– 2 – IEC 63093-6:2018 © IEC 2018
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Primary dimensions . 6
4.1 General . 6
4.2 Dimensions of ETD-cores . 7
4.2.1 Principal dimensions . 7
4.2.2 Effective parameter and A values . 7
min
4.3 Dimensional limits for coil formers. 8
4.4 Pin locations and base outlines . 9
4.5 Pin diameter . 12
5 Marking . 12
6 Mounting . 12
7 Limits of surface irregularities . 12
7.1 General . 12
7.2 Examples of surface irregularities . 12
7.3 Chips and ragged edges . 13
7.3.1 General. 13
7.3.2 Chips and ragged edges on the mating surfaces . 13
7.3.3 Chips and ragged edges on the other surfaces . 13
7.4 Cracks . 16
7.5 Flash . 16
7.6 Pull-outs . 16
7.7 Crystallites . 17
7.8 Pores . 18
Annex A (normative) Derived standards . 19
Annex B (normative) Example of dimensions for gauges to check the dimensions of
ETD-cores complying with this document . 22
B.1 General . 22
B.2 Procedure and requirements . 22
Annex C (informative) Reference of allowable areas of chips . 23
Bibliography . 24

Figure 1 – Dimensions of ETD-cores . 7
Figure 2 – Essential dimensions of coil formers . 8
Figure 3 – Pin locations and base outlines viewed from the upper-side of the board . 10
Figure 4 – Examples of surface irregularities . 13
Figure 5 – Chip location for ETD-cores . 14
Figure 6 – Crack and pull-out locations for ETD-cores . 16
Figure 7 – Crystallite location for ETD-cores . 17
Figure 8 – Pore location for ETD-cores . 18
Figure A.1 – Main dimensions of coil formers . 20
Figure B.1 – Gauge dimensions . 22

Table 1 – Dimensions of ETD-cores . 7
Table 2 – Effective parameter and A values . 8
min
Table 3 – Dimensional limits for coil formers . 9
Table 4 – Area and length reference for visual inspection . 15
Table 5 – Limits for cracks . 17
Table A.1 – Main dimensions of coil formers . 21
Table B.1 – Gauge dimensions . 22
Table C.1 – Allowable areas of chips for ETD-cores . 23

– 4 – IEC 63093-6:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FERRITE CORES – GUIDELINES ON DIMENSIONS
AND THE LIMITS OF SURFACE IRREGULARITIES –

Part 6: ETD-cores for use in power supplies

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
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governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
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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
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
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7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
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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 63093-6 has been prepared by IEC technical committee 51:
Magnetic components, ferrite and magnetic powder materials.
This first edition cancels and replaces the first edition of IEC 62317-6 published in 2015 and
the second edition of IEC 60424-3 published in 2015. This edition constitutes a technical
revision.
This edition includes the following significant technical changes with respect to
IEC 62317-6:2015 and IEC 60424-3:2015:
a) This document integrates IEC 62317-6:2015 and IEC 60424-3:2015;
b) Table 1 – Allowable areas of chips for ETD-cores, of IEC 60424-3:2015, has been moved
to Annex C (informative) of this document.

The text of this standard is based on the following documents:
CDV Report on voting
51/1215/CDV 51/1234/RVC
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.
A list of all parts in the IEC 63093 series, published under the general title Ferrite cores –
Guidelines on dimensions and the limits of surface irregularities, 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.
A bilingual version of this publication may be issued at a later date.

– 6 – IEC 63093-6:2018 © IEC 2018
FERRITE CORES – GUIDELINES ON DIMENSIONS
AND THE LIMITS OF SURFACE IRREGULARITIES –

Part 6: ETD-cores for use in power supplies

1 Scope
This part of IEC 63093 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of ETD-cores made of ferrite and the essential
dimensions of coil formers to be used with them, as well the effective parameter values to be
used in calculations involving them. It also gives guidelines on allowable limits of surface
irregularities applicable to ETD-cores.
The specifications contained in this document are useful in negotiations between ferrite core
manufacturers and users about surface irregularities.
The use of derived standards which give more detailed specifications of component parts
while still permitting compliance with this document is discussed in Annex A.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this
...

IEC 63093-6 ®
Edition 1.0 2018-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Ferrite cores – Guidelines on dimensions and the limits of surface
irregularities –
Part 6: ETD-cores for use in power supplies

Noyaux ferrites – Lignes directrices relatives aux dimensions et aux limites
des irrégularités de surface –
Partie 6: Noyaux ETD utilisés dans les alimentations électriques

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
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IEC 63093-6 ®
Edition 1.0 2018-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Ferrite cores – Guidelines on dimensions and the limits of surface

irregularities –
Part 6: ETD-cores for use in power supplies

Noyaux ferrites – Lignes directrices relatives aux dimensions et aux limites

des irrégularités de surface –

Partie 6: Noyaux ETD utilisés dans les alimentations électriques

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.100.10 ISBN 978-2-8322-1088-2

– 2 – IEC 63093-6:2018 © IEC 2018
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Primary dimensions . 6
4.1 General . 6
4.2 Dimensions of ETD-cores . 7
4.2.1 Principal dimensions . 7
4.2.2 Effective parameter and A values . 7
min
4.3 Dimensional limits for coil formers. 8
4.4 Pin locations and base outlines . 9
4.5 Pin diameter . 12
5 Marking . 12
6 Mounting . 12
7 Limits of surface irregularities . 12
7.1 General . 12
7.2 Examples of surface irregularities . 12
7.3 Chips and ragged edges . 13
7.3.1 General. 13
7.3.2 Chips and ragged edges on the mating surfaces . 13
7.3.3 Chips and ragged edges on the other surfaces . 13
7.4 Cracks . 16
7.5 Flash . 16
7.6 Pull-outs . 16
7.7 Crystallites . 17
7.8 Pores . 18
Annex A (normative) Derived standards . 19
Annex B (normative) Example of dimensions for gauges to check the dimensions of
ETD-cores complying with this document . 22
B.1 General . 22
B.2 Procedure and requirements . 22
Annex C (informative) Reference of allowable areas of chips . 23
Bibliography . 24

Figure 1 – Dimensions of ETD-cores . 7
Figure 2 – Essential dimensions of coil formers . 8
Figure 3 – Pin locations and base outlines viewed from the upper-side of the board . 10
Figure 4 – Examples of surface irregularities . 13
Figure 5 – Chip location for ETD-cores . 14
Figure 6 – Crack and pull-out locations for ETD-cores . 16
Figure 7 – Crystallite location for ETD-cores . 17
Figure 8 – Pore location for ETD-cores . 18
Figure A.1 – Main dimensions of coil formers . 20
Figure B.1 – Gauge dimensions . 22

Table 1 – Dimensions of ETD-cores . 7
Table 2 – Effective parameter and A values . 8
min
Table 3 – Dimensional limits for coil formers . 9
Table 4 – Area and length reference for visual inspection . 15
Table 5 – Limits for cracks . 17
Table A.1 – Main dimensions of coil formers . 21
Table B.1 – Gauge dimensions . 22
Table C.1 – Allowable areas of chips for ETD-cores . 23

– 4 – IEC 63093-6:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FERRITE CORES – GUIDELINES ON DIMENSIONS
AND THE LIMITS OF SURFACE IRREGULARITIES –

Part 6: ETD-cores for use in power supplies

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 63093-6 has been prepared by IEC technical committee 51:
Magnetic components, ferrite and magnetic powder materials.
This first edition cancels and replaces the first edition of IEC 62317-6 published in 2015 and
the second edition of IEC 60424-3 published in 2015. This edition constitutes a technical
revision.
This edition includes the following significant technical changes with respect to
IEC 62317-6:2015 and IEC 60424-3:2015:
a) This document integrates IEC 62317-6:2015 and IEC 60424-3:2015;
b) Table 1 – Allowable areas of chips for ETD-cores, of IEC 60424-3:2015, has been moved
to Annex C (informative) of this document.

The text of this standard is based on the following documents:
CDV Report on voting
51/1215/CDV 51/1234/RVC
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.
A list of all parts in the IEC 63093 series, published under the general title Ferrite cores –
Guidelines on dimensions and the limits of surface irregularities, 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 63093-6:2018 © IEC 2018
FERRITE CORES – GUIDELINES ON DIMENSIONS
AND THE LIMITS OF SURFACE IRREGULARITIES –

Part 6: ETD-cores for use in power supplies

1 Scope
This part of IEC 63093 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of ETD-cores made of ferrite and the essential
dimensions of coil formers to be used with them, as well the effective parameter values to be
used in calculations involving them. It also gives guidelines on allowable limits of surface
irregularities applicable to ETD-cores.
The specifications contained in this document are useful in negotiations between ferrite core
manufacturers and users about surface irregularities.
The use of derived standards which give more detailed specifications of component parts
while still permitting compliance with this document is discussed in Annex A.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC 60205, Calculation of the effective parameters of magnetic piece parts
IEC 60401-1, Terms and nomenclature for cores made of magnetically soft ferrites – Part 1:
Terms used for physical irregularities
IEC 60424-1, Ferrite cores – Guidelines on the limits of surface irregularities – Part 1:
General specification
3 Terms and definitions
For the purpose of this document, the terms and definitions given in IEC 60401-1 and
IEC 60424-1 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
4 Primary dimensions
4.1 General
Compliance with the following requirements ensures the mechanical interchangeability of
complete assemblies and coil formers.

4.2 Dimensions of ETD-cores
4.2.1 Principal dimensions
The principal dimensions of ETD-cores shall be those given in Figure 1 and Table 1. The
dimensions of the cores can be checked by means of gauges. By way of example, possible
dimensions for these gauges are given in Annex B. In order to facilitate production, it can be
necessary to use gauges with dimensions that differ from those given in Annex B, although no
relaxation of the requirements for the dimensions of the cores given in Table 1 is permitted.
The dimensions specified in Table 1 are illustrated in Figure 1.
C
B
D
IEC
Figure 1 – Dimensions of ETD-cores
Table 1 – Dimensions of ETD-cores
A B C D E F
Size mm mm mm mm mm mm
Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max.
ETD 19 19,1 20,1 13,5 13,8 7,2 7,6 9,2 9,6 14,4 15,4 7,2 7,6
ETD 24 23,8 25,0 14,3 14,6 8,2 8,8 9,9 10,3 18,0 19,2 8,2 8,8
ETD 29 29,0 30,6 15,6 16,0 9,2 9,8 10,7 11,3 22,0 23,4 9,2 9,8
ETD 34 33,4 35,0 17,1 17,5 10,5 11,1 11,8 12,4 25,6 27,0 10,5 11,1
ETD 39 38,2 40,0 19,6 20,0 12,2 12,8 14,2 15,0 29,3 30,9 12,2 12,8
ETD 44 43,0 45,0 22,1 22,5 14,4 15,2 16,1 16,9 32,5 34,1 14,4 15,2
ETD 49 47,6 49,8 24,5 24,9 15,9 16,7 17,7 18,5 36,1 37,9 15,9 16,7
ETD 54 53,2 55,8 27,4 27,8 18,5 19,3 19,8 20,6 40,1 42,3 18,5 19,3
ETD 59 58,4 61,2 30,8 31,2 21,2 22,1 22,0 22,9 43,6 45,8 21,2 22,1

4.2.2 Effective parameter and A values
min
The effective parameter values of a pair of cores whose dimensions comply with 4.2.1 shall
be as given in Table 2. For the definitions of these parameters and their calculations,
reference shall be made to IEC 60205.
F
E
A
– 8 – IEC 63093-6:2018 © IEC 2018
Table 2 – Effective parameter and A values
min
a
C C L A V A
1 2 e e e min
Size
−1 −3 2 3 2
mm mm mm mm mm mm
−3
ETD 19 1,253 9 28,412 × 10 55,3 44,1 2 440 39,5
−3
ETD 24 1,053 7 17,811 × 10 62,3 59,2 3 690 55,0
−3
ETD 29 0,927 07 70,8 76,4 5 410 70,9
12,139 × 10
−3
ETD 34 0,814 49 8,387 9 × 10 79,1 97,1 7 680 91,6
−3
ETD 39 0,742 00 5,940 1 × 10 92,7 125 11 600 123
−3
ETD 44 0,599 18 104 173 17 900 172
3,462 8 × 10
−3
ETD 49 0,542 45 115 211 24 200 209
2,569 2 × 10
−3
ETD 54 0,455 01 1,625 1 × 10 127 280 35 700 280
−3
ETD 59 0,382 24 141 368 51 700 366
1,038 9 × 10
NOTE 1 Manufacturers can indicate more precise values in their catalogues than those given in Table 2.
NOTE 2 The above values have been calculated using the method given in IEC 60205.
a
IEC 60205 shall be referred to for the definition of A .
min
4.3 Dimensional limits for coil formers
The essential dimensions of coil formers suitable for use with a pair of ETD-cores shall be as
given in Figure 2 and Table 3.
d
d
IEC
Figure 2 – Essential dimensions of coil formers
f
f
e
Table 3 – Dimensional limits for coil formers
e f f d d
1 2 1 2
Size mm mm mm mm mm
Max. Max. Min. Max. Min.
ETD 19 14,1 9,8 7,8 18,2 15,9
ETD 24 17,6 11,0 9,0 19,6 17,1
ETD 29 21,6 12,0 10,0 21,2 18,7
ETD 34 25,2 13,6 11,3 23,4 20,9
ETD 39 28,8 15,3 13,0 28,2 25,7
ETD 44 32,0 17,7 15,4 32,0 29,5
ETD 49 35,5 19,5 17,0 35,2 32,2
ETD 54 39,5 22,1 19,6 39,3 36,3
ETD 59 43,0 24,9 22,4 43,7 40,7

4.4 Pin locations and base outlines
These shall be as shown in Figure 3, in which the base is viewed in the mounting direction, i.e.
from the upper side of the printed wiring board.

– 10 – IEC 63093-6:2018 © IEC 2018
4 × (2m)
5 × (2m)
ETD 19
ETD 24
6 × (2m)
m
Earth
6 × (2m)
points
ETD 29 ETD 34
8 × (2m)
m
7 × (2m)
m
Earth Earth
points points
ETD 39 ETD 44
IEC
The module, designated as m, as shown in the grid plan, may be 2,50 mm or 2,54 mm.
Figure 3 – Pin locations and base outlines viewed
from the upper-side of the board (1 of 2)
6 × (2m)
7 × m
5 × (2m)
1,6
1,6
2m
1,6
5 × (2m)
9 × m
7 × (2m)
1,6
1,6
2m
1,6
2m
9 × (2m)
m
Earth
points
ETD 49
11 × (2m)
ETD 54
12 × (2m)
ETD 59
IEC
The module, designated as m, as shown in the grid plan, may be 2,50 mm or 2,54 mm.
Figure 3 (2 of 2)
9 × (2m)
10 × (2m)
8 × (2m)
1,6
2m
1,6
3,2
1,6
3,2
– 12 – IEC 63093-6:2018 © IEC 2018
4.5 Pin diameter
Coil former terminations (pins) shall be accepted by a gauge with 1,2 mm holes on a true
position.
5 Marking
Where a coil former is fitted with termination pins conforming to a 2,50 mm module, it shall be
clearly and indelibly marked with the letter m, in such a position that it can be readily seen in
the completed component.
6 Mounting
According to their sizes and respective weights, it is recommended that two of the largest
cores (ETD 54 and ETD 59) be fixed on the printed board by means of screws located at two
opposite sides of their coil formers.
Concerning smaller sizes such as ETD 19 and ETD 24, no mounting assemblies are defined.
It is recommended that the two cores be fixed by glue or adhesive tape.
7 Limits of surface irregularities
7.1 General
Surface irregularities are defined in IEC 60424-1.
7.2 Examples of surface irregularities
Figure 4 shows different examples of surface irregularities of an ETD-core.

Cracks
Flash
Ragged
edge
Pull-out
Crystallite
Chip
Pore
IEC
Figure 4 – Examples of surface irregularities
7.3 Chips and ragged edges
7.3.1 General
The minimum area is taken as 0,5 mm , to be distinguishable to the naked eye.
Examples of allowable areas of chips are given in Annex C.
7.3.2 Chips and ragged edges on the mating surfaces
The areas of the chips located on the mating surfaces (chip 1 and chip 1' irregularities in
Figure 5) shall not exceed the following limits:
• the cumulative area of the chips shall be less than 6 % of the mating surface (whether
gapped or ungapped) of the centre pole;
• the total length of the ragged edges shall be less than 25 % of the perimeter of the
relevant surface.
7.3.3 Chips and ragged edges on the other surfaces
The allowable areas of chips on the other surfaces are doubled as compared to the limits for
the mating surface (see Figure 5).
The rule for ragged edges is the same as that for the mating surface.

– 14 – IEC 63093-6:2018 © IEC 2018
Mating surfaces
Chip 1'
Chip 2
Chip 1
Ragged
edges
IEC
Figure 5 – Chip location for ETD-cores

Area and length reference for visual inspection is given in Table 4.
Table 4 – Area and length reference for visual inspection

– 16 – IEC 63093-6:2018 © IEC 2018
7.4 Cracks
The limits for cracks at various locations shown in Figure 6 are given in Table 5.
7.5 Flash
There shall be no flash extending from the core into the wire slot (see Figure 6).
7.6 Pull-outs
For ETD-cores, the cumulative area of pull-outs of the core shall be less than 25 % of the
total respective surface area (see Figure 6).
H
S1''
S1
S1'
S3''
S3
S2
S7
S2''
S2'
S5
T
S5'
Flash
S5'' Pull-out
S4''
S3'
S4'''
S4''
S4
W
S6
S6'
IEC
Figure 6 – Crack and pull-out locations for ETD-cores

Table 5 – Limits for cracks
Type Location Limits for Limits for
single crack multiple cracks
Mating surface of centre
S1 and S1' < 25 % of dimension W < 50 % of dimension W
pole
S1" Corner of centre pole Not acceptable Not acceptable
S2 and S2' Mating surface of outer < 25 % of dimension H < 25 % of dimension H
leg
S2" Side of outer leg < 25 % of dimension H < 25 % of dimension H
S3 and S3" Centre pole < 25 % of dimension W < 25 % of dimension W
S3' Bottom corner of centre < 25 % of dimension W < 25 % of dimension W
pole / back wall and outer
leg/back wall
S4 Bottom corner of outer leg < 25 % of dimension T < 25 % of dimension T
/ back wall
S4' and S4" Back wall < 25 % of dimension T < 25 % of dimension T
S4''' Back wall < 50 % of dimension W < 100 % of dimension W
S5 and S5' and S5" Outer leg < 50 % of dimension W < 100 % of dimension W
S6 Back surface < 50 % of dimension W < 100 % of dimension W
S6' Back surface < 25 % of dimension W < 25 % of dimension W
S7 Corner of outer leg Not acceptable Not acceptable

7.7 Crystallites
Figure 7 shows an example of crystallite location on ETD-cores:
• a single area of the crystallites located on any surface shall be less than 2 % of the
respective surface area;
• the cumulative area of the crystallites located on any surface shall be less than 4 % of the
respective surface area (see Figure 7).
Crystallite
IEC
Figure 7 – Crystallite location for ETD-cores

– 18 – IEC 63093-6:2018 © IEC 2018
7.8 Pores
Figure 8 shows an example of pore location on ETD-cores:
• the number of pores located on the same surface shall not exceed two. The total number
of pores located on all surfaces shall not exceed five;
• a hole with an area larger than 1 mm on any surface is not acceptable.
Pore
IEC
Figure 8 – Pore location for ETD-cores

Annex A
(normative)
Derived standards
Clauses 4 to 5 of this document establish the values for the principal dimensions of core
assemblies and wound coil formers and enable full interchangeability for components
complying with this document to be achieved.
Parties interested in making or using ETD-cores may find it desirable to lay down local
standards for everyday use that show the dimensions and tolerances in greater detail than
those in Clause 4 and correspond to the state of the art in that area. These are known as
derived standards. When doing so, care should be taken not to exclude any other type of
ETD-core meeting the requirements in this document that would also satisfy the performance
specification valid for a specific case.
It should be noted that, even if a component complies with a derived standard and with the
requirements of Clause 4 of this document, therefore permitting core assemblies and coil
formers to be freely interchanged, its constituent parts may not necessarily be
interchangeable.
When requirements lead to the establishment of a national standard, the relevant national
standardization body is strongly requested to insert a note in such a national standard stating
that:
a) the national standard is in accordance with the dimensional requirements of IEC 63093-6,
but that more details are given in order to promote the practical use of the standard;
b) other solutions are possible within the framework of IEC 63093-6, and should not be
excluded if the resulting cores and coil formers are functionally interchangeable with those
in accordance with the national standard.
By way of example, a possible derived standard for coil formers is given in Figure A.1.
An example of a standard for the main dimensions of coil formers for ETD-cores meeting the
requirements of this document is given in Figure A.1 and Table A.1.

– 20 – IEC 63093-6:2018 © IEC 2018
h
a
e d
f d
1 2
f
p × (2m) q × (2m)
IEC
a) ETD-cores ETD 29, ETD 34, ETD 39, ETD 44 and ETD 49
h
h
a
e d
f d
1 2
f
p × (2m) q × (2m)
IEC
b) ETD-cores ETD 54 and ETD 59
The module, designated as m, may be 2,50 mm or 2,54 mm.
Figure A.1 – Main dimensions of coil formers

H
H
Table A.1 – Main dimensions of coil formers
a e f f d d h h H p q
1 2 1 2 4
Size mm mm mm mm mm mm mm mm mm
Max. Max. Max. Min. Max. Min. Max. Max. Max.
ETD 29 35,3 21,6 11,8 10,0 21,2 19,0 35,2 – 25,0 6 5
ETD 34 39,6 25,2 13,4 11,4 23,4 20,9 42,8 – 34,9 6 5
ETD 39 44,6 28,9 15,1 13,1 28,2 25,7 47,8 – 37,6 7 6
ETD 44 49,6 32,0 17,5 15,5 32,0 29,5 52,5 – 40,4 8 7
ETD 49 54,5 35,7 19,0 17,0 35,2 32,2 57,5 – 42,9 9 8
ETD 54 61,5 39,4 21,6 19,6 39,3 36,3 61,4 64,0 43,0 11 9
ETD 59 66,9 42,9 24,6 22,4 43,7 40,7 66,4 69,0 46,0 12 10

– 22 – IEC 63093-6:2018 © IEC 2018
Annex B
(normative)
Example of dimensions for gauges to check the dimensions
of ETD-cores complying with this document
B.1 General
The gauges shall be in accordance with Table B.1 and its associated Figure B.1.
d
c
b
IEC
Figure B.1 – Gauge dimensions
Table B.1 – Gauge dimensions
a b c d e f
Size mm mm mm mm mm mm
Min. Max. Min. Max. Min. Min. Min. Max. Min. Max.
ETD 19 20,105 20,115 9,20 9,21 14,0 14,0 14,385 14,395
...