IEC 61333:2019

IEC 61333 ®
Edition 2.0 2019-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Marking on ferrite cores
Marquage des noyaux ferrites
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IEC 61333 ®
Edition 2.0 2019-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Marking on ferrite cores
Marquage des noyaux ferrites
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.030 29.100.10 ISBN 978-2-8322-7247-3

– 2 – IEC 61333:2019 © IEC 2019
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Marking locations . 5
5 Marking content . 7
5.1 General . 7
5.2 Material identification code . 7
5.3 A value or gap length . 7
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Bibliography . 9

Figure 1 – Examples of marking locations for U-cores . 5
Figure 2 – Examples of marking locations for E-cores . 6
Figure 3 – Examples of marking locations for ring-cores . 6
Figure 4 – Examples of marking locations for planar-cores . 6
Figure 5 – Examples of marking locations for RM-cores . 6
Figure 6 – Examples of marking locations for PQ-cores . 7
Figure 7 – Examples of marking locations for pot-cores . 7

Table 1 – Examples of the coding of the A value . 8
L
Table 2 – Examples of coding of the gap length . 8

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MARKING ON FERRITE CORES
FOREWORD
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International Standard IEC 61333 has been prepared by IEC technical committee 51:
Magnetic components, ferrite and magnetic powder materials.
This second edition cancels and replaces the first edition published in 1996. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition：
a) the title of the document was changed;
b) the scope of this document was expanded;
c) the marking position instructions for ring cores, planar cores, RM-cores, PQ-cores and
pot-cores were added in Clause 4 with a few additional descriptions;
d) the four-digit-maximum limit of material identification code has been deleted in 5.2;
e) in Table 1, the unit of A has been changed from "nH" to "nH/N ".
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– 4 – IEC 61333:2019 © IEC 2019
The text of this International Standard is based on the following documents:
CDV Report on voting
51/1247/CDV 51/1290/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.
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.
MARKING ON FERRITE CORES
1 Scope
This document specifies marking locations and a coding system of marking on ferrite cores.
An alphanumerical marking printed or attached to cores reduces the risk of incorrect assembly,
mixing of materials and/or mixing of gapped cores on an assembly line. The markings of the
inductance factor A value or of the gap length are especially important to avoid this kind of
L
problem, and their coding system is specified in this document.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
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 Marking locations
The recommended marking locations for the various core shapes are indicated in Figure 1 to
Figure 7:
– the shaded parts in Figures 1 to 7 represent the marking locations;
– the marking locations of ETD-, EER-, EC-, EFD- and EP-cores refer to the E-core.

Figure 1 – Examples of marking locations for U-cores

– 6 – IEC 61333:2019 © IEC 2019

Figure 2 – Examples of marking locations for E-cores

Figure 3 – Examples of marking locations for ring-cores

Figure 4 – Examples of marking locations for planar-cores

Figure 5 – Examples of marking locations for RM-cores

Figure 6 – Examples
...