TC 68 - Magnetic alloys and steels

IEC TR 63304:2021(E) describes the general principle and technical details of the methods of measurement of the DC magnetic properties of permanent magnet materials in an open magnetic circuit using a superconducting magnet (SCM).
This method is applicable to permanent magnet materials, such as those specified in IEC 60404-8-1, the properties of which are presumed homogeneous throughout their volume.
There are two methods:
– the SCM-Vibrating Sample Magnetometer (VSM) method;
– the SCM-Extraction method.
This document also describes methods to correct the influence of the self-demagnetizing field in the test specimen on the demagnetization curve measured in an open magnetic circuit. The magnetic properties are determined from the corrected demagnetization curve.
NOTE These SCM-methods can determine the magnetic properties of permanent magnet materials with coercivity higher than 2 MA/m. The methods of measurement in a closed magnetic circuit specified in IEC 60404-5 can lead to significant measurement error due to saturation effects in the pole pieces of yoke for the magnetic materials with coercivity higher than 1,6 MA/m (see IEC 60404-5).

IEC 60404-8-7:2020 is available as IEC 60404-8-7:2020 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 60404-8-7:2020 defines the grades of cold-rolled grain-oriented electrical steel strip and sheet in nominal thicknesses of 0,20 mm, 0,23 mm, 0,27 mm, 0,30 mm and 0,35 mm. In particular, it gives general requirements, magnetic properties, geometric characteristics, tolerances and technological characteristics, as well as inspection procedures. This document applies to Goss textured grain-oriented electrical steel strip and sheet supplied in the final annealed condition in coils or sheets, and intended for the construction of magnetic circuits. The grades are grouped into three classes:
- conventional grades;
- high permeability grades;
- magnetic domain refined high permeability grades.
They correspond to Class C22 of IEC 60404-1.
This edition includes the following significant technical changes with respect to the previous edition:
- insertion of a third class of grain-oriented electrical steels for magnetic domain refined high permeability grades;
- introduction of the single sheet tester (SST) method as reference measurement method for this third class of material together with a conversion factor for transposition of the SST measurement results to equivalent Epstein values;
- update of the electrical steel range to take account of the current offers and demands of grades.

IEC 60404-8-5:2020(E) defines the grades of electrical steel strip and sheet with specified mechanical properties and magnetic polarization. In particular, it gives general requirements, mechanical properties, magnetic polarization, geometric characteristics, tolerances and technological characteristics, as well as inspection procedures.
This document applies to electrical steel strip and sheet intended for the construction of poles and rims of rotating electrical machines.
The grades are grouped into two classes according to their manufacturing process:
- hot-rolled grades;
- cold-rolled grades.
They correspond to Class D21 of IEC 60404-1.
This edition includes the following significant technical changes with respect to the previous edition:
a) extension of the range of products to include the improved grades;
b) division of "flatness" into "edge wave (wave factor)" and "residual curvature" in consistent with IEC 60404-9;
c) change length of test specimen for determinations of geometrical characters from 2 m to 1 m.

IEC 60404-7:2019 specifies a method of measurement of the coercivity of magnetic materials in an open magnetic circuit. This document is applicable to all magnetic materials with coercivities from 0,2 A/m to 160 kA/m.
This edition includes the following significant technical changes with respect to the previous edition:  
Clause 1: The scope includes a more detailed description of the magnetic materials which applies to this standard;
Clause 4: Figure 2 – circuit diagram for methods A and B was simplified and the fluxgate probes inside the solenoid have been added;
Clause 7: Compensation for the earth’s magnetic field and for static and dynamic magnetic noise fields has been added;
Clause 8: Magnetic shielding of the measuring region has been added;
9.2.2: The measuring methods for local and integral measurement of the flux in the test specimen have been separated and the limitations in size and shape of the test specimen have been considered.
9:3: The method C with a VSM (Vibrating Sample Magnetometer) has been moved from 9.3 to the Annex B.
The term "complex shaped test specimen" has been replaced in several clauses by "test specimen different from ellipsoids".
The character of Annex A has been changed from “informative” to “normative”.

IEC 60404-9:2018 specifies the measurement and test methods for the determination of the following geometrical characteristics of electrical steel strip and sheet:
– edge wave (wave factor);
– residual curvature;
– edge camber;
– deviation from the shearing line (internal stress);
– burr height.
This document applies to electrical steel strip and sheet intended for the construction of magnetic circuits and corresponding to Classes B2, C21, C22 and C23 of IEC 60404-1.
This edition includes the following significant technical changes with respect to the previous edition:
a. revision of terms and definitions;
b. specification of the length of test specimens for the determinations of edge wave (wave factor) and edge camber;
c. addition of the horizontal method for the determination of residual curvature, and a note that informs about a safety concern of the vertical method;
d. clarification that the burr height was characterized by the maximum value;
e. addition of the measuring procedure using a hand-held micrometer to determine the burr height.

IEC 60404-13:2018 specifies the methods used for determining the resistivity, density and stacking factor of grain-oriented and non-oriented electrical steel strip and sheet. These quantities are necessary to establish the physical characteristics of the material. Moreover, the density is necessary to allow specified values of the magnetic polarization, resistivity and stacking factor to be determined.
Since these properties are functions of temperature, the measurements will be made at an ambient temperature of (23 ±5) °C except when specified in this document.
This edition includes the following significant technical changes with respect to the previous edition:  
the sequence of the density and resistivity sections is changed and the title of the document revised to reflect this;
the van-der-Pauw method (Method R2) is also applicable to Epstein strip specimens;
the gas pyknometer method is introduced, and the liquid immersion method and the calculation method based on the chemical composition are quoted;
the requirements of the stacking factor section, such as the tolerance of the dimensions of the test specimen and the repeatability of measurement, are changed;
an example of the apparatus for determination of the resistivity using a rectangular sheet, which was previously part of the main body of the text, is moved to constitute informative Annex A;
an example of the determination of the density by using the gas pyknometer method is added as an informative Annex B;
an example of the determination of density based on the calculation of silicon and aluminium contents is added as an informative Annex C.

IEC TR 63114:2018(E) describes the general principle and technical details of the reverse bend test method used for evaluating the ductility of electrical steel strip and sheet. This test method is applicable to Epstein test strip specimens obtained from non-oriented and grain-oriented electrical steel of any grade. The test specimens shall not be annealed.

IEC 60404-8-11:2018 defines the grades of Fe-based amorphous strip delivered in the semi‑processed state, i.e. without final heat treatment, of nominal thickness 0,025 mm. Other nominal thicknesses in the range from 0,020 mm to 0,030 mm can be specified by agreement between the manufacturer and the purchaser at the time of enquiry and order. In particular, it gives general requirements, magnetic properties, geometric characteristics, tolerances and technological characteristics, as well as inspection procedures.
This document applies to the rapidly-solidified Fe-based amorphous strip supplied in coils with as-cast edges and intended for the construction of magnetic circuits.
The grades are grouped into two classes:
- conventional grades;
- high permeability grades.
They correspond to Class I1 of IEC 60404-1.

IEC 60404-16:2018 is applicable to Fe-based amorphous strips specified in IEC 60404-8-11 for the measurement of AC magnetic properties at frequencies up to 400 Hz.
The object of this part is to define the general principles and technical details of the measurement of the magnetic properties of Fe-based amorphous strips by means of a single sheet tester.
The contents of the corrigendum of November 2018 have been included in this copy.

IEC 60404-8-8:2017(E) defines the grades of thin non-oriented electrical steel strip and sheet in nominal thicknesses of 0,05 mm, 0,10 mm, 0,15 mm, 0,20 mm, 0,25 mm, 0,30 mm and 0,35 mm and of thin grain-oriented electrical steel strip and sheet in nominal thicknesses of 0,05 mm, 0,10 mm, 0,15 mm and 0,18 mm. In particular, it gives general requirements, magnetic properties, geometric characteristics and tolerances, technological characteristics, as well as inspection procedures.
NOTE For thin non-oriented electrical steel strip and sheet, other nominal thicknesses (i.e. 0,12 mm, 0,18 mm, 0,23 mm and 0,27 mm) can be agreed between the manufacturer and the purchaser.
This document applies to electrical steel strip and sheet supplied in the finally annealed condition in coils or sheets and intended for the construction of magnetic circuits predominantly used at frequencies in the range from 100 Hz to 10 kHz.
This edition includes the following significant technical changes with respect to the previous edition:
- extension of the range of electrical steels to include the improved grades.

IEC 60404-8-7:2017 is available as IEC 60404-8-7:2017 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 60404-8-7:2017 defines the grades of cold-rolled grain-oriented electrical steel strip and sheet in nominal thicknesses of 0,23 mm, 0,27 mm, 0,30 mm and 0,35 mm. In particular, it gives general requirements, magnetic properties, geometric characteristics, tolerances and technological characteristics, as well as inspection procedures. This document applies to Goss textured grain-oriented electrical steel strip and sheet supplied in the final annealed condition in coils or sheets, and intended for the construction of magnetic circuits.
The grades are grouped into two classes:
– conventional grades;
– high permeability grades, including grades which may be delivered in the domain refined condition. They correspond to Class C22 of IEC 60404-1.
This fourth edition cancels and replaces the third edition published in 2008. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
– extension of the range of electrical steels to include the improved grades.

IEC TR 62981:2017(E), which is a Technical Report, provides the results of international exercises and comparisons focusing on achieving the knowledge of the statistical performance of single sheet tester (SST) measurements made on grain-oriented electrical steel. These experiments aim at specifying obligatory reference values, measured by the single sheet test method, for the grading of high permeability (P grades) grain-oriented (g.-o.) materials, independently from the Epstein classification as it is practiced today. Besides this, Epstein test measurements have been made in order to gain more up-to-date statistical performance for comparison with the SST statistical characteristics. A few experiments were carried out aiming at improved knowledge on the systematic error performance of the SST, i.e. they were to determine the correlation between the quality of insulation separating laminations in the SST yokes and the measured loss.

IEC 60404-8-6:2016 specifies the general requirements, magnetic properties, geometric characteristics and tolerances as well as inspection procedures for pure iron, silicon-iron, nickel-iron and cobalt-iron. The materials are in the form of bar, billet, sheet, strip or wire. The alloys covered correspond to those defined by classes A, C1, C2, E1 to E4 and F1 to F3 in IEC 60404-1. This edition includes the following significant technical changes with respect to the previous edition: Removal of Table 2b).

IEC 60404-1:2016 is available as IEC 60404-1:2016 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 60404-1:2016 is intended to classify commercially available magnetic materials. The term "magnetic materials" denotes substances where the application requires the existence of ferromagnetic or ferrimagnetic properties. The classification of magnetic materials is based upon the generally recognized existence of two main groups of products:
- soft magnetic materials (coercivity less than or equal to 1 000 A/m);
- hard magnetic materials (coercivity greater than 1 000 A/m). This edition includes the following significant technical changes with respect to the previous edition:
a) Removal of all tables and values describing typical properties of the material to be consistent with the aim of the document to be a classification and not a specification.
b) Enlargement of the Ni content for the classes E1 and E3.
c) Enlargement of the Co content for the classes F3.
d) Addition of a new class: U5 bonded rare earth-iron-nitrogen magnets.

IEC 60404-10:2016 is available as IEC 60404-10:2016 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 60404-10:2016(E) is applicable to grain-oriented and non-oriented electrical steel strip and sheet for measurements of a.c. magnetic properties in the frequency range 400 Hz to 10 000 Hz. The object of this document is to define the general principles and the technical details of the measurement of magnetic properties of electrical steel strip and sheet by means of an Epstein frame. This edition includes the following significant technical changes with respect to the previous edition:
a) adaption to modern measurement and evaluation methods, in particular the introduction of the widely spread digital sampling method for the acquisition and evaluation of the measured data;
b) introduction of formal changes which adapt this standard to other standards of the 60404 series;
c) revision of the problem of the air flux compensation taking account of the condition of the higher frequencies;
d) revision of the capacitive coupling of mutual inductor windings together with the consideration of the alternative method of numerical air flux compensation.
The contents of the corrigendum of March 2018 have been included in this copy.

IEC 60404-5:2015 is available as IEC 60404-5:2015 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 60404-5:2015 is to define the method of measurement of the magnetic flux density, magnetic polarization and the magnetic field strength and also to determine the demagnetization curve and recoil line of permanent magnet materials. This edition includes the following significant technical changes with respect to the previous edition:
- adaption of the measurement methods and test conditions to newly introduced magnetically hard materials with coercivity values HcJ higher than 2 MA/m;
- update of the temperature conditions to allow the measurement of new materials with high temperature coefficients.

IEC 60404-8-1:2015 specifies minimum values for the principal magnetic properties of, and dimensional tolerances for, technically important magnetically hard materials (permanent magnets). For information purposes only, this part of IEC 60404 provides values for the densities of the materials and the ranges of their chemical compositions. Some additional physical data and mechanical reference values concerning the magnetic materials are given for information and comparison purposes. This edition includes the following significant technical changes with respect to the previous edition:
a) recently developed anisotropic Sm-Fe-N bonded magnets are included;
b) high energy ferrites with La and Co as substituents are included.

IEC/TR 62797:2013(E) provides the results of an international comparison of measurements of the magnetic moment, using vibrating sample magnetometers (VSM) and superconducting quantum interference device (SQUID) magnetometers. The basic object of this comparison is to verify the degree of reproducibility of the method employed as a prerequisite for the prospective development of a related IEC measuring standard.

IEC 60404-8-4:2013 defines the grades of cold-rolled non-oriented electrical steel strip and sheet in nominal thicknesses of 0,35 mm, 0,50 mm, 0,65 mm and 1,00 mm. It specifies general requirements, the magnetic properties, geometric characteristics and tolerances, and technological characteristics, as well as the inspection procedure. This standard applies to materials supplied in the fully annealed condition intended for the construction of magnetic circuits. It does not apply to semi-processed material. This edition includes the following significant technical changes with respect to the previous edition:
- Deletion of the dates for all normative references;
- Introduction of the new grades M210-35A 5 and M230-50A 5.

IEC 60404-15:2012 specifies a solenoid method, a magnetic moment method, a magnetic balance method and a permeability meter method for the determination of the relative magnetic permeability of feebly magnetic materials (including austenitic stainless steel). The magnetic balance and permeability meter methods are both comparison methods calibrated using reference materials to determine the value of the relative magnetic permeability of the test specimen.

IEC 60404-11:1991+A1:1998+A2:2012 is intended to define a measurement method for the determination of the characteristics of surface insulation resistance of magnetic sheet and strip. This method is applicable to magnetic sheet and strip insulated on one or both surfaces and is suitable for manufacturing control in the application of insulation coatings. This consolidated version consists of the first edition (1991), its amendment 1 (1998) and its amendment 2 (2012). Therefore, no need to order amendments in addition to this publication.

IEC/TR 62581:2010(E) describes the general principles and technical details of the measurement of the magnetostriction of single sheet specimens preferably 500 mm long and 100 mm wide and Epstein strip specimens, specified in IEC 60404-2, of electrical steel by means of optical sensors and accelerometers. These methods are applicable to test specimens obtained from electrical steel sheets and strips of any grade. The characteristics of magnetostriction are determined for a sinusoidal induced voltage, for specified peak values of magnetic polarization and for a specified frequency. The measurements are made at an ambient temperature of 23 °C +/- 5 °C on test specimens which have first been demagnetized.

IEC 60404-3:1992+A1:2002+A2:2009 defines the general principles and the technical details of the measurement of the magnetic properties of magnetic sheets, at power frequencies, by means of a single sheet tester. This tester is applicable to flat plate specimens obtained from magnetic sheets and strips of any quality. The magnetic characterictics are determined for a sinusoidal induced voltage, for specified peak values of magnetic polarization and for a specified frequency.  This consolidated version consists of the second edition (1992), its amendment 1 (2002), its amendment 2 (2009) and its corrigendum (2009). Therefore, no need to order amendments in addition to this publication.

The contents of the corrigendum of December 2009 have been included in this copy.

IEC 60404-8-10:2009 specifies the general requirements, magnetic properties, geometric characteristics and tolerances as well as inspection procedures for magnetic materials used primarily for relays. This standard applies to pure iron, non-alloyed and alloyed steel and ferritic stainless steel products usually delivered in either the semi-processed or fully-processed state. These materials correspond to classes A, B, C and D.3 of IEC 60404-1. This second edition cancels and replaces the first edition published in 1994 and constitutes a technical revision. The main modifications from the previous edition of the standard are as follows:
- introduction of the ferritic stainless steels and the fully-processed state in the scope of the standard (see Clause 1);
- modification of the designation with the letter R at the beginning and the condition and state at the end (see Clause 5);
- introduction of the new grades R160 and R320 (see Table 2);
- modification of the requirements for the heat treatment of test specimens for semi-processed material (see Subclause 8.3.1);
- indication in Bibliography of standards referred to in this standard as an information.

IEC/TR 62517:2009(E) describes the magnetizing behaviour of permanent magnets in detail covering:
- the relationship between the applied magnetic field strength and the effectively acting internal field strength;
- the initial state prior to magnetization;
- the magnetizing behaviour of all common types of permanent magnets subdivided according to the dominant coercivity mechanisms, namely the nucleation type for sintered Ferrites, RE-Fe-B and SmCo5 magnets, the pinning type for carbon steel and Sm2Co17 magnets and the single domain type for nano-crystalline RE-Fe-B, Alnico and Cr-Fe-Co magnets;
- the recommended magnetizing field strengths for modern permanent magnets compiled in a comprehensive table.

IEC/TR 62518:2009(E) describes the temperature behaviour of rare earth sintered magnets in detail for use in designing magnetic circuits exposed to elevated temperatures. The temperature behaviour of SmCo5, Sm2Co17 and Nd-Fe-B sintered magnets is described. The various changes of open circuit flux which can occur due to temperature are discussed in Clause 4. The long term stability of the magnets is discussed in Clause 5. The experimental procedures are described in Clause 6. Results of the measurements of the flux loss occurring at the ambient temperature after heating isothermally at 50 °C, 75 °C, 100 °C, 125 °C, 150 °C and 200 °C for up to 1000 h are given in Clause 7. The effect of length to diameter ratio (L/D) of the magnet samples and the influence of HcJ on the flux loss were also studied. The results are discussed in Clause 8. The data in this technical report was provided by the Institute of Electrical Engineers of Japan (IEEJ) and its subcommittees. This data has been gathered from the members of these sub-committees. The temperature stability correlated with the complex corrosion behaviour and the spin re-orientation phenomena at cryogenic temperatures will not be given in this technical report.

Describes the terminology and two measuring methods, namely: the ring method and the permeameter method. Both methods use a test specimen in a closed magnetic circuit. Description of the test equipment and the electric circuits is given. This consolidated version consists of the second edition (1995) and its amendment 1 (2000). Therefore, no need to order amendment in addition to this publication.

Applies to grain oriented and non-oriented electrical sheet and strip for a.c. measurements of magnetic properities at frequencies up to 400 Hz and for d.c. magnetic measurements. Defines the general principles and the technical details of the measurement of the magnetic properties of electrical steel sheet and strip by means of an Epstein frame. The a.c. magnetic characteristics are determined for sinusoidal induced voltages, for specified peak values of magnetic polarization and for a specified frequency. This consolidated version consists of the third edition (2000) and its amendment 1 (2008). Therefore, no need to order amendment in addition to this publication.
The contents of the corrigendum of March 2018 have been included in this copy.

The contents of the corrigendum of March 2018 have been included in this copy.

This technical report reviews methods for measurement of the magnetic loss of soft magnetic materials under the condition of magnetic polarization which includes higher harmonic components. Nowadays, by computer aided testing (CAT), a.c. magnetic properties of electrical steel sheets can be measured under various measuring conditions automatically. For example, the magnetic loss in the presence of higher harmonic frequency components of magnetic polarization can be measured using the arbitrary waveform synthesizer, digitiser and computer. The present standard methods (IEC 60404-2, IEC 60404-3 and IEC 60404-10) for the determination of specific total loss are restricted to the sinusoidal waveform of magnetic polarization, and these standards are still important for the characterization of core materials. However, actual waveforms of magnetic polarization in the electrical machines and transformers always include higher harmonic polarizations, and nowadays electrical machines can be designed using numerical methods including higher harmonics. But for these conditions, there is still no standard testing method.

Applies to magnetic material intended for the construction of magnetic circuits. These materials correspond respectively to classes C.21 and B.2 of IEC 60404-1: 2000. This standard defines the grades of cold-rolled electrical non-oriented non-alloyed (non alloyed steel is that steel the basic constituent of which is iron containing alloying elements in amounts smaller than the limiting values fixed by ISO 4948 1) or alloyed (alloyed steel is that steel the basic constituent of which is iron containing alloying elements in amounts equal to or greater than the limiting values fixed by ISO 4948 1) steel sheet and strip delivered in the semi-processed state, i.e. without final heat treatment, of nominal thicknesses given in Tables 1 and 2. It specifies general requirements, the magnetic properties, the geometrical characteristics and tolerances, technological characteristics as well as the inspection procedure.

Reviews methods for measuring magnetically hard materials using pulsed field magnetometers. The methods of measurement of the magnetic properties of magnetically hard materials have been specified in IEC 60404-5 for closed magnetic circuits and in IEC 60404-7 for open magnetic circuits. The measurement result of the magnetic properties of magnetically hard materials at elevated temperatures is given in IEC 61807. Pulsed field magnetometers have been developed to provide rapid measurement facilities to match high speed production rates with 100 % quality control. The object of this report is to describe the principles and practical implications of pulsed field magnetometry in order to enable the full potential of the technique to be considered, including its application using small and large magnets of varying geometries, to various magnetic field strengths and frequencies.

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 agreed between the purchaser and the steel producer, where applicable. The classification is used in conjunction with the various specifications for cold rolled electrical steels (see the standards in the IEC 60404-8 series in Clause 2).

Defines the general principles and the technical details of the measurement of the magnetic properties of magnetic sheets, at power frequencies, by means of a single sheet tester. This tester is applicable to flat plate specimens obtained from magnetic sheets and strips of any quality. The magnetic characterictics are determined for a sinusoidal induced voltage, for specified peak values of magnetic polarization and for a specified frequency. This consolidated version consists of the second edition (1992) and its amendment 1 (2002). Therefore, no need to order amendment in addition to this publication.

Applicable to all ferromagnetic materials. It is particularly aimed at the measurement of the magnetic dipole moment of permanent magnet (magnetically hard) materials and the measurement of the specific saturation magnetic polarization of cemented carbide materials having a ferromagnetic binder. To describe the general principles of the determination of the magnetic dipole moment of a ferromagnetic material specimen using a detection coil in an open magnetic circuit. By including a means of magnetizing the material to saturation, the saturation magnetic dipole moment can also be determined. In addition, the average magnetic polarization of a test specimen can be derived from the measurement of its magnetic dipole moment and volume. The calibration of magnetic moment coil systems and the measurement of the magnetic dipole moment of feebly magnetic materials can also be determined using this method. Measurements are normally performed at room temperature but measurements at other temperatures can be conducted by heating or cooling the volume occupied by the test specimen within the detection coil. The measurement of remanence, coercivity, maximum energy product and other parameters can be made in a closed magnetic circuit as described in IEC 60404-4 and IEC 60404-5. Measurement of the coercivity HcJ of soft and semi-hard materials can also be performed in an open circuit as described in IEC 60404-7.

Describes the terminology and two measuring methods, namely: the ring method and the permeameter method. Both methods use a test specimen in a closed magnetic circuit. Description of the test equipment and the electric circuits is given. This consolidated version consists of the second edition (1995) and its amendment 1 (2000). Therefore, no need to order amendment in addition to this publication.

Provides methods for measuring magnetically hard materials, at elevated temperatures. Magnetically hard materials (permanent magnet materials) are classified in IEC 60404-1 and their properties are specified in IEC 60404-8-1. The methods of measurement of the magnetic properties of magnetically hard materials at room temperature have been specified in IEC 60404-5 for closed magnetic circuits and in IEC 60404-7 for open magnetic circuits, respectively. The applications of magnetically hard materials are now expanding to elevated temperatures and it is therefore required to specify and guarantee the magnetic properties of these materials over their working temperature range. In IEC 60404-8-1 temperature coefficients of remanence (or saturation) and J-coercivity have been specified in addition to basic properties such as maximum magnetic energy product ((BH)max), remanence (Br), B-coercivity (HcB), J-coercivity (HcJ), recoil permeability (µrec) and density.

Defines a measurement method for the determination of the characteristics of surface insulation resistance of magnetic sheet and strip. Applicable to magnetic sheet and strip insulated on one or both surfaces and is suitable for manufacturing control in the application of insulation coatings. This consolidated version consists of the first edition (1991) and its amendment 1 (1998). Therefore, no need to order amendment in addition to this publication.