SIST EN 10342:2026
(Main)Magnetic materials - Classification of surface insulations of electrical steel sheet, strip and laminations
Magnetic materials - Classification of surface insulations of electrical steel sheet, strip and laminations
This document establishes a classification of surface insulations for electrical steel sheet, strip and laminations according to their general composition, relative insulating ability and function.
These surface insulations are either oxide layers or applied coatings.
The purpose of this classification is to create a nomenclature for the various types of surface insulations and to assist users of surface insulations by providing general information about the chemical nature and use of the surface insulations.
It is not the intent of this classification to specify insulation requirements in terms of specific values of surface insulation resistance. Such requirements are to be agreed between the purchaser and the steel producer, where applicable.
The classification is to be used in conjunction with the various specifications for cold rolled electrical steels (see Clause 2).
Magnetische Werkstoffe - Einteilung der Isolationen auf Elektroblech und ‑band und daraus gefertigten Stanzteilen
In diesem Dokument wird eine Einteilung der Isolationen für Elektroblech und -band und daraus gefertigte Stanzteile vorgenommen. Diese Einteilung erfolgt auf Grundlage der allgemeinen chemischen Zusammensetzung der Isolationen, der relativen Isolierfähigkeit sowie des Einsatzgebietes.
Diese Isolationen sind entweder Oxidschichten oder aufgetragene Beschichtungen.
Zweck dieser Einteilung ist, eine Nomenklatur für verschiedene Isolationstypen zu schaffen und den Anwender durch die Bereitstellung allgemeiner Informationen über die chemische Zusammensetzung und Einsatzmöglichkeiten bei der Auswahl der Isolationen zu unterstützen.
Diese Einteilung hat nicht zum Ziel, für die Isolationsanforderungen spezifische Werte zum Isolations-widerstand festzulegen. Gegebenenfalls müssen diese Anforderungen zwischen dem Besteller und dem Stahl¬hersteller vereinbart werden.
Die Einteilung ist in Verbindung mit den verschiedenen Normen für kaltgewalztes Elektroblech und -band (siehe Abschnitt 2) zu nutzen.
Matériaux magnétiques - Classification des isolations de surface des tôles, bandes et lamelles magnétiques en acier
Le présent document établit une classification des isolations de surface des tôles, bandes et lamelles en acier électrique en fonction de leur composition générale, leur aptitude relative à l'isolement et leur fonction.
Ces isolations de surface sont soit des couches d'oxyde soit des revêtements appliqués.
L'objectif de cette classification est de créer une nomenclature pour les différents types d'isolations de surface et d'aider les utilisateurs d'isolations de surface en fournissant des informations générales sur la nature chimique et l'utilisation des isolations de surface.
L'intention de cette classification n'est pas de spécifier des exigences relatives à l'isolation en termes de valeurs spécifiques de résistance d’isolation de surface. De telles exigences sont à convenir entre l'acheteur et le producteur d'acier, le cas échéant.
La classification est à utiliser conjointement avec les diverses spécifications pour les aciers électriques laminés à froid (voir l'Article 2).
Magnetni materiali - Klasifikacija površinskih izolacij elektropločevine, trakov in laminatov
General Information
- Status
- Published
- Public Enquiry End Date
- 24-Dec-2024
- Publication Date
- 22-Dec-2025
- Technical Committee
- IFEK - Ferrous metals
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 18-Dec-2025
- Due Date
- 22-Feb-2026
- Completion Date
- 23-Dec-2025
Relations
- Effective Date
- 22-May-2024
Overview
EN 10342:2025 - published by CEN - defines a clear classification of surface insulations for electrical steel sheet, strip and laminations. The standard covers oxide layers and applied coatings, grouping them by general chemical composition, relative insulating ability and functional use. Its purpose is to provide a common nomenclature (EC-0 through EC-6 and subtypes) to assist steel producers, manufacturers and purchasers in selecting and specifying surface insulations for magnetic steels. EN 10342:2025 supersedes EN 10342:2005 and adds new entries (notably EC-3-B).
Key topics and requirements
- Scope and intent: Classification only - EN 10342 does not set mandatory surface insulation resistance values; those are agreed between purchaser and supplier.
- Insulation types: Descriptions of oxide layers and coatings, including:
- EC-0 / EC-1: Natural or furnace-formed oxide layers.
- EC-2: Inorganic “mill glass” (magnesium silicate) for wound core transformers.
- EC-3 / EC-3-B: Organic varnish/enamel; EC-3-B is a self-bonding (B-stage → C-stage) varnish.
- EC-4 / EC-4-AS: Phosphate/chemical-treated coatings; EC-4-AS is an anti‑stick variant.
- EC-5 family (EC-5-G / -N / -P / -AS): Enhanced inorganic/ceramic-filled coatings for higher insulation and specific grain/non‑oriented uses; EC-5-AS is anti‑stick.
- EC-6: Organic-based coatings with inorganic fillers for high insulation (large rotating machines).
- Performance notes: Guidance on punchability, weldability, annealing and burn‑off temperature resistance (e.g., EC-3 typically not suitable for stress-relief annealing and is generally rated up to ~180 °C; EC-5-G withstands stress-relief annealing up to 845 °C; EC-5-N and EC-6 tolerate burn-off in the 300–550 °C range).
- Testing: Surface insulation resistance measurements referenced to EN IEC 60404-11; methods and acceptance criteria are to be agreed contractually.
Applications and users
- Target users: steel manufacturers, transformer and motor designers, rotor/stator rebuilders, stampers, procurement/specification engineers and test laboratories.
- Typical applications: wound core transformers (EC-2), stamped laminations for motors and transformers (EC-3, EC-5, EC-6), anti‑stick coatings for heat-treatment processing, and self-bonding coatings for automated lamination bonding.
Related standards
- EN 10106, EN 10107, EN 10341, EN 10265, EN 10303 (cold-rolled electrical steels)
- EN IEC 60404-11 (surface insulation resistance measurement)
- IEC 60050-221 (terminology)
Keywords: EN 10342, surface insulations, electrical steel, lamination coatings, oxide layer, surface insulation resistance, CEN, EC-5-G, EC-3-B.
Frequently Asked Questions
SIST EN 10342:2026 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Magnetic materials - Classification of surface insulations of electrical steel sheet, strip and laminations". This standard covers: This document establishes a classification of surface insulations for electrical steel sheet, strip and laminations according to their general composition, relative insulating ability and function. These surface insulations are either oxide layers or applied coatings. The purpose of this classification is to create a nomenclature for the various types of surface insulations and to assist users of surface insulations by providing general information about the chemical nature and use of the surface insulations. It is not the intent of this classification to specify insulation requirements in terms of specific values of surface insulation resistance. Such requirements are to be agreed between the purchaser and the steel producer, where applicable. The classification is to be used in conjunction with the various specifications for cold rolled electrical steels (see Clause 2).
This document establishes a classification of surface insulations for electrical steel sheet, strip and laminations according to their general composition, relative insulating ability and function. These surface insulations are either oxide layers or applied coatings. The purpose of this classification is to create a nomenclature for the various types of surface insulations and to assist users of surface insulations by providing general information about the chemical nature and use of the surface insulations. It is not the intent of this classification to specify insulation requirements in terms of specific values of surface insulation resistance. Such requirements are to be agreed between the purchaser and the steel producer, where applicable. The classification is to be used in conjunction with the various specifications for cold rolled electrical steels (see Clause 2).
SIST EN 10342:2026 is classified under the following ICS (International Classification for Standards) categories: 29.030 - Magnetic materials; 77.140.50 - Flat steel products and semi-products. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN 10342:2026 has the following relationships with other standards: It is inter standard links to SIST EN 10342:2005. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST EN 10342:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-februar-2026
Magnetni materiali - Klasifikacija površinskih izolacij elektropločevine, trakov in
laminatov
Magnetic materials - Classification of surface insulations of electrical steel sheet, strip
and laminations
Magnetische Werkstoffe - Einteilung der Isolationen auf Elektroblech und ‑band und
daraus gefertigten Stanzteilen
Matériaux magnétiques - Classification des isolations de surface des tôles, bandes et
lamelles magnétiques en acier
Ta slovenski standard je istoveten z: EN 10342:2025
ICS:
29.030 Magnetni materiali Magnetic materials
77.140.50 Ploščati jekleni izdelki in Flat steel products and semi-
polizdelki products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 10342
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2025
EUROPÄISCHE NORM
ICS 29.030 Supersedes EN 10342:2005
English Version
Magnetic materials - Classification of surface insulations of
electrical steel sheet, strip and laminations
Matériaux magnétiques - Classification des isolations Magnetische Werkstoffe - Einteilung der Isolationen
de surface des tôles, bandes et lamelles magnétiques en auf Elektroblech und -band und daraus gefertigten
acier Stanzteilen
This European Standard was approved by CEN on 11 November 2025.
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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 10342:2025 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Classification of surface insulations of electrical steel, strip and laminations . 5
European foreword
This document (EN 10342:2025) has been prepared by Technical Committee CEN/TC 459/SC 8 “Steel
sheet and strip for electrical applications”, the secretariat 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 June 2026, and conflicting national standards shall be
withdrawn at the latest by June 2026.
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.
This document supersedes EN 10342:2005.
— the normative references have been updated;
— in Table 1, insulation designation EC-3-B has been added.
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 organisations 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.
1 Scope
This document establishes a classification of surface insulations for electrical steel sheet, strip and
laminations according to their general composition, relative insulating ability and function.
These surface insulations are either oxide layers or applied coatings.
The purpose of this classification is to create a nomenclature for the various types of surface insulations
and to assist users of surface insulations by providing general information about the chemical nature
and use of the surface insulations.
It is not the intent of this classification to specify insulation requirements in terms of specific values of
surface insulation resistance. Such requirements are to be agreed between the purchaser and the steel
producer, where applicable.
The classification is to be used in conjunction with the various specifications for cold rolled electrical
steels (see Clause 2).
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.
EN 10106, Cold rolled non-oriented electrical steel strip and sheet delivered in the fully processed state
EN 10107, Grain-oriented electrical steel strip and sheet delivered in the fully processed state
EN 10265, Magnetics materials — Specification for electrical steel strip and sheet with specified
mechanical properties and magnetic polarisation
EN 10303, Thin magnetic steel strip and sheet for use at medium frequencies
EN 10341, Cold rolled electrical non-alloy and alloy steel sheet and strip delivered in the semi-processed
state
EN IEC 60404-11, Magnetic materials — Part 11: Methods of measurement of the surface insulation
resistance of electrical steel strip and sheet
IEC 60050-221, International Electrotechnical Vocabulary (IEV) — Part 221: Magnetic materials and
components
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-221 and in EN 10106,
EN 10107, EN 10341, EN 10265, EN IEC 60404-11 and EN 10303 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
4 Classification of surface insulations of electrical steel, strip and laminations
Table 1 specifies the classification of surface insulations of electrical steel sheet, strip and laminations.
Table 1 — Classification of surface insulation of electrical steel, strip and laminations
Insulation
Insulation description – Characteristics – Typical application, limits of use
designation
EC-0 An oxide layer that is formed naturally on the steel surface during electrical steel
manufacture. This oxide layer is thin, tightly adherent and provides sufficient surface
insulation resistance for many types of small cores.
This oxide layer will withstand normal stress relief annealing temperatures.
If subjected to a user’s anneal after stamping, the surface insulation resistance of this
oxide layer m
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