Marking on ferrite cores

IEC 61333:2019 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 AL value or of the gap length are especially important to avoid this kind of problem, and their coding system is specified in this document.
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 AL has been changed from "nH" to "nH/N2".

Kennzeichnung von Ferritkernen

Marquage des noyaux ferrites

L'IEC 61333:2019 spécifie les emplacements de marquage et un système de codification pour le marquage des noyaux ferrites. Un marquage alphanumérique imprimé ou fixé sur les noyaux réduit le risque de mauvais assemblage, de mélange de matériaux et/ou de mélange de noyaux à entrefer sur les lignes d'assemblage. Les marquages de la valeur de l'inductance spécifique AL ou de la longueur d'entrefer sont particulièrement importants pour éviter ce type de problème, et leur système de codification est spécifié dans le présent document.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) le titre du document a été modifié;
b) le domaine d'application du présent document a été étendu;
c) les instructions concernant les emplacements de marquage des noyaux toroïdaux, planaires, RM, PQ et P ont été ajoutées à l'Article 4, ainsi que plusieurs descriptions complémentaires;
d) la limite à quatre éléments au maximum pour le code d'identification du matériau a été supprimée en 5.2;
e) dans le Tableau 1, l'unité utilisée pour la valeur AL n'est plus "nH" et a été remplacée par "nH/N2".

Označevanje feritnih jeder

General Information

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6060 - National Implementation/Publication (Adopted Project)
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SIST EN IEC 61333:2021
SIST EN 61333:2002
Označevanje feritnih jeder
Marking on ferrite cores
Ta slovenski standard je istoveten z: EN IEC 61333:2019
29.100.10 Magnetne komponente Magnetic components
SIST EN IEC 61333:2021 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 61333:2021

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SIST EN IEC 61333:2021



October 2019
ICS 29.035; 29.100.10 Supersedes EN 61333:1998 and all of its amendments
and corrigenda (if any)
English Version
Marking on ferrite cores
(IEC 61333:2019)
Marquage des noyaux ferrites Kennzeichnung von Ferritkernen
(IEC 61333:2019) (IEC 61333:2019)
This European Standard was approved by CENELEC on 2019-09-03. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 61333:2019 E

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SIST EN IEC 61333:2021
EN IEC 61333:2019 (E)
European foreword
The text of document 51/1247/CDV, future edition 2 of IEC 61333, prepared by IEC/TC 51 "Magnetic
components, ferrite and magnetic powder materials" was submitted to the IEC-CENELEC parallel vote
and approved by CENELEC as EN IEC 61333:2019.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2020-06-03
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2022-09-03
document have to be withdrawn

This document supersedes EN 61333:1998 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice
The text of the International Standard IEC 61333:2019 was approved by CENELEC as a European
Standard without any modification.

In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60062 NOTE Harmonized as EN 60062


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SIST EN IEC 61333:2021

IEC 61333


Edition 2.0 2019-07





Marking on ferrite cores

Marquage des noyaux ferrites







ICS 29.030 29.100.10 ISBN 978-2-8322-7247-3

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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SIST EN IEC 61333:2021
– 2 – IEC 61333:2019 © IEC 2019
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
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
Table 2 – Examples of coding of the gap length . 8

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SIST EN IEC 61333:2021
IEC 61333:2019 © IEC 2019 – 3 –


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