IMKF - Magnetic components and ferrite materials

This part of IEC 62025 specifies a test method for the non-electrical characteristics of the
surface mounted device (SMD) inductors to be used for electronic and telecommunication
equipment. The object of this part of this document is to define methods for measuring
mechanical performance only. As the reliability performances and specifications relative to
non-electrical performances are defined in IEC 62211, detailed measuring methods for
mechanical performance of reliability testing are defined in this document.

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".

IEC 63093-2:2020 specifies the dimensions that are of importance for mechanical interchangeability for a preferred range of pot-cores made of ferrite, and the dimensional limits for coil formers to be used with them, as well as the effective parameter values to be used in calculations involving them. It also gives guidelines on the allowable limits of surface irregularities applicable to pot-cores in accordance with the relevant generic specification.
The selection of core sizes and shapes for this document is based on the philosophy of including those sizes which are industrial standards, either by inclusion in a national standard, or by broad-based use in industry. See IEC 62317-1 for more detail concerning the philosophy of selecting core sizes to be included.
The general considerations upon which the design of this range of cores is based are given in Annex A.
This first edition cancels and replaces the first edition of IEC 62317-2 published in 2010. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition of IEC 62317-2:
a) addition of the limits of surface irregularities;
b) Table 4 and Table 5 are updated in accordance with IEC 60205:2016.

This part of IEC 62024 specifies the measuring methods of the rated direct current limits for
small inductors.
Standardized measuring methods for the determination of ratings enable users to accurately
compare the current ratings given in various manufacturers’ data books.
This document is applicable to leaded and surface mount inductors with dimensions according
to IEC 62025-1 and generally with rated current less than 22 A, although inductors with rated
current greater than 22 A are available that fall within the dimension restrictions of this
document (no larger than a 12 mm × 12 mm footprint approximately). These inductors are
typically used in DC-to-DC converters built on PCBs, for electric and telecommunication
equipment, and small size switching power supply units.
The measuring methods are defined by the saturation and temperature rise limitations
induced solely by direct current.

IEC 63093-3:2020 specifies the dimensions that are of importance for mechanical interchangeability for a preferred range of half pot-cores made of ferrite, intended to be used in inductive proximity switches. Half pot-cores for inductive proximity switches are also called PS-cores.
The selection of core sizes and shapes for this document is based on the philosophy of including those sizes and shapes which are industrial standards, either by inclusion in a national standard, or by broad-based use in industry.
This part of IEC 63093 can also be considered as a sectional specification useful in the negotiations between ferrite core manufacturers and customers about surface irregularities. It provides guidelines on the allowable limits of surface irregularities applicable to PS-cores in accordance with the relevant generic specification.
This first edition cancels and replaces the first edition of IEC 62323, published in 2005. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition of IEC 62323:
a) addition of the limits surface irregularities.

This part of IEC 63182 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of ring-cores (also called toroids) made of magnetic
powder, the effective parameter values to be used in calculations involving them, and gives
guidelines on allowable limits of surface irregularities applicable to coated ring-cores.
The selection of core sizes for this document is based on the philosophy of including those
sizes which are industrial standards, meaning that they are in broad-based use within the
industry. This document is considered as a sectional specification useful in the negotiations
between magnetic powder core manufacturers and users about surface irregularities.

This document describes a number of tests for use in determining the significant parameters
and performance characteristics of transformers and inductors for use in electronics and
telecommunication equipment. These test methods are designed primarily for transformers
and inductors used in all types of electronics applications that can be involved in any
specification for such components. Even though these tests can be useful to the other types
of transformers used in power distribution applications in utilities, industry, and others, the
tests discussed in this document can supplement or complement the tests but are not
intended to replace the tests in standards for transformers. Some of the tests described are
intended for qualifying a product for a specific application, while others are test practices used
for manufacturing and customer acceptance testing. The test methods described here include
those parameters most commonly used in the electronics transformer and inductor industry:
electric strength, resistance, power loss, inductance, impedance, balance, transformation
ratio and many others used less frequently.

This part of IEC 63093 specifies the dimensions and allowable limits of surface irregularities
of ferrite cores.
It is intended that this document includes ferrite cores which are widely used and referenced
in industry, either because they are included in national standards, or because they are seen
to have broad-based use in industry. Where applicable, it is intended that the existing
industrial name for each standard part appears with the part within this series.
It is intended that this document excludes ferrite cores which are specialty cores with limited
use. Also, special cores which are only marginal variations upon standard cores are excluded.
A ferrite core produced by only one or two suppliers can generally be considered a specialty
part, and not suitable as a standard core within this series. A ferrite core produced by three or
more competing manufacturers can generally be considered to be a candidate to be included
in this series.
IEC publishes electrical standards for families of ferrite cores, as well as this series of
dimensional standards for families of ferrite cores. Modifications to the ferrite cores listed in
one type of standard are reflected in the other type.
This document is considered as a general specification useful in the dialogue between ferrite
core suppliers and users about surface irregularities.

This part of IEC 63093 specifies the shapes and dimensions of ferrite cores for inductive
components (transformers and chokes), whose the coil is typically made of multi-layer boards
(or the coil is part of the motherboard), and the effective parameter values used in
calculations. This document gives guidelines on allowable limits of surface irregularities
applicable to planar-cores as well.
This document is considered as a sectional specification useful in the negotiation between
ferrite core suppliers and users about surface irregularities.
The general consideration upon which the design of this range of cores is based is given in
Annex A.

This part of IEC 60401 provides a nomenclature of the most frequent surface, bulk and shape
irregularities relevant to cores made of soft ferrites (magnetic oxides). Most irregularities are
graphically exemplified as visual aids. A general recommendation is also given in Annex A for
a consistent scheme for specifying the exact location of the irregularity, combining a general
name for the location with more detailed qualifiers of the specified location. This document
can also be useful as a terminology reference when preparing technical documentation,
irregularity inspection specifications, etc.
This document also presents a method for defining the designation nomenclature for the
major physical attributes of soft ferrite core shapes. The purpose of this document is to
facilitate uniform usage of dimensional characters by manufacturers, specifiers, and users
when describing core dimensions on drawings, in tables, and on catalogue specification
sheets.

This document specifies a test method for the mechanical strength of cores made of magnetic
oxides. This test method is suitable for most of the E-cores, ETD-cores, I-cores and ringcores
but other core types such as U-cores could be tested according to a derived method
agreed by the parties concerned. This document is also applicable to the mechanical strength
measurement of magnetic powder cores.

This part of IEC 63182 specifies the dimensions of magnetic powder cores.
It is intended that this document will include magnetic powder cores which are widely used and
referenced in industry, either because they are included in national standards, or because they
are seen to have broad-based use in industry. Where applicable, it is intended that the existing
industrial name for each powder core will appear with the part within the IEC 63182 series.
This document also gives guidelines on the allowable limits of surface irregularities of magnetic
powder cores. It is considered as a general specification useful in the dialogue between
magnetic powder core manufacturers and users about surface irregularities.

This part of IEC 63093 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of EC-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 EC-cores.
The specifications contained in this document are useful in negotiations between ferrite core
manufacturers and customers about surface irregularities.

This part of IEC 63093 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of ring-cores, also called toroid cores, and the
effective parameter values to be used in calculations involving them. It also gives guidelines
on allowable limits of surface irregularities applicable to ring-cores.
This document is a specification useful in the negotiations between ferrite core manufacturers
and users about surface irregularities.

This part of IEC 63093 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of E-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 E-cores.
The specifications contained in this document are useful in negotiations between ferrite core
manufacturers and customers about surface irregularities.
The use of derived standards, which give more detailed specifications of component parts
while still permitting compliance with this standard, is discussed in Annex A.

This part of IEC 63093 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of EFD-cores, the essential dimensions of coil formers
to be used with them, and the effective parameter values to be used in calculations involving
them. It also gives guidance on the allowable limits of surface irregularities applicable to EFDcores
in accordance with the relevant generic specification.
The selection of core sizes for this document is based on the philosophy of including those
sizes which are industrial standards, either by inclusion in national standards, or by broadbased
use in industry.
This document is a specification useful in the negotiation between ferrite core manufacturers
and users about surface irregularities.
The general considerations that the design of this range of cores is based upon are given in
Annex A.

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.

This part of IEC 63093 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of PQ-cores and low-profile PQI-cores made of ferrite,
and the locations of their terminal pins on a 2,54 mm printed wiring grid in relation to the base
outlines of the cores. It also gives guidance on allowable limits of surface irregularities
applicable to PQ-cores in accordance with the relevant generic specification.
The selection of core sizes for this document is based on the philosophy of including those
sizes which are industrial standards, either by inclusion in a national standard, or by
broad-based use in industry.
This document is a specification useful in the negotiations between ferrite core manufacturers
and customers about surface irregularities.
The general considerations that the design of this range of cores is based upon are given in
Annex A.

This part of IEC 63093 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of EP-cores made of ferrite, the essential dimensions
of coil formers to be used with them and the locations of their terminal pins on a 2,50 mm
printed wiring grid in relation to the base outlines of the cores and the effective parameter
values to be used in calculations involving them. It also gives guidelines on allowable limits of
surface irregularities applicable to EP-cores.
The specifications contained in this document are useful in negotiations between ferrite core
manufacturers and users about surface irregularities.
The general considerations upon which the design of this range of cores is based are as given
in Annex A.

This part of IEC 63093 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of RM-cores and low-profile RM-cores made of ferrite,
and the locations of their terminal pins on a 2,54 mm printed wiring grid in relation to the base
outlines of the cores. It also gives guidance on allowable limits of surface irregularities
applicable to RM-cores in accordance with the relevant generic specification.
The selection of core sizes for this document is based on the philosophy of including those
sizes which are industrial standards, either by inclusion in a national standard, or by broadbased
use in industry.
This document is a specification useful in the negotiations between ferrite core manufacturers
and customers about surface irregularities.
The general considerations that the design of this range of cores is based upon are given in
Annex A.

IEC - Corrected version

This part of IEC 62024 specifies electrical characteristics and measuring methods for the nanohenry range chip inductor that is normally used in high frequency (over 100 kHz) range.

This part of IEC 63093 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of EER-cores made of ferrite, the essential
dimensions of coil formers to be used with them as well the effective parameter values to be
used in calculations involving them, and gives guidelines on allowable limits of surface
irregularities applicable to EER-cores.
This document is a specification useful in the negotiations between ferrite core manufacturers
and customers 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.

This document is applicable to inductive components (chokes and transformers) based on magnetically soft materials. These are components based especially on laminated iron sheets, iron powder materials (including alloys), as well as ferrites and amorphous or crystalline metal band cores.
Winding assemblies mean wire winding assemblies as well as multilayer and stacking technologies of planar technology including coils based on non-magnetic materials. Discrete type components and the different types of surface mount inductive components (SMD) are also considered in this document.
The reliability of assemblies of inductive components based on several technologies such as glued types, types with clamps (clips), impregnated (varnished) types as well as (vacuum) potted types can also be checked with this document.
The subsequent determinations can be applied either for the primary qualification of inductive components or for all manners of requalification examinations (design, process, change of production facility). They can also be applied for the monitoring of products out of actual manufacturing processes.
This document sets up a broad basis of electric and mechanical criteria of failure test procedures.
If manufacturers advertise compliance with this standard in their data sheets, customers can request data to demonstrate compliance with this standard. The customers can also request the product to be in compliance with this standard by a recognised body.
Customers and manufacturers can elect to perform additional testing and acceptance criteria different than those defined in this standard.

This International Standard lays down uniform rules for the calculation of the effective parameters of closed circuits of ferromagnetic material.

This part of IEC 62317 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of ring-cores, also called toroid cores, and the effective
parameter values to be used in calculations involving them.
The selection of core sizes for this document is based on the philosophy of including those sizes
which are industrial standards, meaning that they are in broad-based use within industry. See
IEC 62317-1 for more detail concerning the philosophy of selecting core sizes to be included.

This document specifies classification rules for soft ferrite materials used in inductive
components (inductors and transformers) fulfilling the requirements of the electronic industries.
This document addresses the following issues for ferrite suppliers and users:
• cross-reference between materials from multiple suppliers;
• assistance to customers in understanding the published technical data in catalogues when
comparing multiple suppliers;
• guidance to customers in selecting the most applicable material for each application;
• setting of nomenclature for IEC standards relating to ferrite;
• establishing uniform benchmarks for suppliers for performance in new development of
materials.
The numerical values given in this document are typical values of the parameters (properties) of
the related materials. Direct translation from the material specification into the core specification
is not always easy or possible.
Every detailed material and core specification should be agreed upon between the user and the
manufacturer.

This document specifies marking codes for fixed inductors.
The colour code specified in Clause 3 gives a colour coding for fixed inductors. It is intended for
use with the values of the E3 to E24 series as specified in IEC 60063.
The code specified in Clause 4 gives a system for marking inductance values by means of digits
and letters.
The code specified in Clause 5 gives a system for marking the tolerance on inductance values by
means of letters.
The code specified in Clause 6 gives a system for marking of date codes on fixed inductors by
means of letters and digits.

This part of IEC 60424 provides guidelines on the allowable limits of surface irregularities
applicable to RM-cores in accordance with the relevant generic specification.
This standard should be considered as a sectional specification useful in the negotiations
between ferrite core manufacturers and customers about surface irregularities. Normative
reference

This part of IEC 62317 specifies the dimensions that are of importance for mechanical
interchangeability for ETD-cores made of ferrite, the essential dimensions of coil formers to
be used with them, and the effective parameter values to be used in calculations involving
them.
The use of “derived” standards which give more detailed specifications of component parts
while still permitting compliance with this standard is discussed in Annex A, which also
contains an example of a derived standard for coil formers.

This part of IEC 60401 gives guidelines for a uniform method of presentation for the
properties of magnetically soft ferrite materials and measuring conditions under which they
should be determined. It is intended for use in manufacturers' catalogues of transformer and
inductor cores, in order to aid the comparability of such data. Additional guidance is given for
users and manufacturers concerning testing and specification of reliability for ferrite cores and
for devices using ferrite cores.

This part of IEC 60424 gives guidelines on the allowable limits of surface irregularities of ferrite
cores.
This standard should be considered as a general specification useful in the dialogue between
ferrite core manufacturers and customers about surface irregularities.

This part of IEC 60424 gives guidance on allowable limits of surface irregularities applicable
to ring-cores in accordance with the relevant generic specification defined in IEC 60424-1.
This standard is considered as a sectional specification useful in the negotiations between
ferrite core manufacturers and customers about surface irregularities.

This part of IEC 60424 gives guidelines on allowable limits of surface irregularities applicable
to ETD-cores, EER-cores, EC-cores and E-cores in accordance with the relevant general
specification.
This standard is a specification useful in the negotiations between ferrite core manufacturers
and customers about surface irregularities.

This part of IEC 62317 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of EC-cores, the essential dimensions of coil formers
to be used with them, and the effective parameter values to be used in calculations involving
them.
The selection of core sizes for this standard is based on the philosophy of including those
sizes which are industrial standards, either by inclusion in national standards, or by broadbased
use in industry. See 62317-1 for more detail concerning the philosophy of selecting
core sizes to be included.

This part of IEC 62317 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of PQ-cores and low-profile PQI-cores made of ferrite,
and the locations of their terminal pins on a 2,54 mm printed wiring grid in relation to the base
outlines of the cores.
The selection of core sizes for this standard is based on the philosophy of including those
sizes which are industrial standards, either by inclusion in a national standard, or by broadbased
use in industry.
NOTE See IEC 62317-1 for more detail concerning the philosophy of selecting core sizes to be included.
The general considerations that the design of this range of cores is based upon are given in
Annex A.

This part of IEC 60424 gives guidance on allowable limits of surface irregularities applicable
to PQ-cores in accordance with the relevant generic specification.
This standard is considered as a sectional specification useful in the negotiation between
ferrite core manufacturers and users about surface irregularities.

This part of IEC 62317 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of EP-cores, the essential dimensions of coil formers
to be used with these cores and the locations of their terminal pins on a 2,50 mm printed
wiring grid in relation to the base outlines of the cores, and the effective parameter values to
be used in calculations involving them.
The general considerations upon which the design of this range of cores is based are as given
in Annex A.

This part of IEC 62674 applies to fixed surface mount inductors and ferrite beads. The object of this standard is to define the terms necessary to describe the inductors covered by this standard, provide recommendations for preferred characteristics, recommended performance, test methods and general guidance.

This International Standard provides standard AL values (inductance factors) and their tolerances of Pot, RM, ETD, E, EER, EP, PQ and low-profile gapped ferrite cores.

This part of IEC 60401 presents a method for defining the designation nomenclature for the major physical attributes of soft ferrite core shapes. The purpose of this standard is to facilitate uniform usage of dimensional characters by manufacturers, specifiers, and users when describing core dimensions on drawings, in tables, and on catalogue specification sheets.

This part of IEC 62317 specifies the dimensions that are of importance for mechanical interchangeability for a preferred range of pot-cores made of ferrite, and the dimensional limits for coil formers to be used with them. The selection of core sizes for this standard is based on the philosophy of including those sizes which are industrial standards, either by inclusion in a national standard, or by broadbased use in industry. See IEC 62317-1 for more detail concerning the philosophy of selecting core sizes to be included. The general considerations upon which the design of this range of cores is based are given in Annex A.

This part of IEC 62333 provides characterization of parameters for electromagnetic noise suppression sheet (NSS) for digital devices and equipment used in a frequency range between 30 MHz to 30 GHz. Guidance is given for uniform presentation of the properties of noise suppression sheet, intended for use in manufacturers and users technical data. NSS suppresses noise at its source, rather than absorbing noise at a distance. Therefore NSS is distinguished from RF wave absorbers used in free space.
This standard addresses the following purposes of NSS manufacturers and users:
– it assists users in understanding the published technical data in catalogues;
– it guides users in selecting the most preferable NSS for each application;
– it establishes measurement benchmarking for manufacturers of performance in new
development of NSS; and
– it maintains high reliability of NSS and applied products.
The numerical values given in this standard are typical values of parameters (properties) of the related NSS. The purpose of NSS testing is the benchmarking of materials. Predictions of specific device performance values are not always easy or even possible. Every detailed material and NSS specification should be agreed between the user and the manufacturer.

This part of IEC 60424 gives guidance on allowable limits of surface irregularities applicable to planar-cores in accordance with the relevant generic specification defined in IEC 60424-1. The relations between the main dimensions of planar E-, ER- and EL-cores differ from those of standard cores. For example, the width of planar cores is larger while the total height is much smaller. Also the thickness of the legs is in most cases smaller than compared to standard cores. Therefore the concept of fixed reference dimensions to determine the length of crack limits yield crack lengths which are not acceptable for this type of core. This part of IEC 60424 follows another concept which relates the crack length to dimensions of the surface on which the crack occurs. Also the concept to determine the maximum area of chips based on the total mating surface fails in the case of planar cores. The outer legs of planar cores are much thinner than those of standard cores which makes overlapping and gluing much more difficult. A single chip of maximum size on the outer leg may risk the functionality of the core set. Therefore this standard uses as a reference the mating surface on which the chip occurs. Windings of planar cores are often PCB’s which are glued to the inner surfaces of the planar core. For this reason the inner surfaces of the planar cores need to have a better quality than the inner surfaces of standard cores. This was taken into account by reducing the maximum allowable area of pull outs in the inner surfaces. This standard is considered as a sectional specification useful in the negotiation between ferrite core manufacturers and users about surface irregularities.

This part of IEC 62024 specifies the measuring methods of the rated direct current limits for small inductors. Standardized measuring methods for the determination of ratings enable users to accurately compare the current ratings given in various manufacturers' data books. This standard is applicable to leaded and surface mount inductors with dimensions according to IEC 62025-1 and generally with rated current less than 22 A, although inductors with rated current greater than 22 A are available that fall within the dimension restrictions of this standard (no larger than 12 mm × 12 mm footprint approximately). These inductors are typically used in DC to DC converters built on PCB, for electric and telecommunication equipment, and small size switching power supply units. The measuring methods are defined by the saturation and temperature rise limitations induced solely by direct current.

This part of IEC 62317 specifies the dimensions that are of importance for mechanical interchangeability for a preferred range of EFD-cores, the essential dimensions of coil formers to be used with them, and the effective parameter values to be used in calculations involving them. The selection of core sizes for this standard is based on the philosophy of including those sizes which are industrial standards, either by inclusion in national standards, or by broad-based use in industry. See IEC 62317-1 for more detail concerning the philosophy of selecting core sizes to be included. The general considerations that the design of this range of cores is based upon are given in Annex A.

This part of IEC 62317 specifies the dimensions that are of importance for mechanical interchangeability for a preferred range of PQ-cores and low-profile PQI-cores made of ferrite, and the locations of their terminal pins on a 2,54 mm printed wiring grid in relation to the base outlines of the cores. The selection of core sizes for this standard is based on the philosophy of including those sizes which are industrial standards, either by inclusion in a national standard, or by broad-based use in industry. See IEC 62317-1 for more detail concerning the philosophy of selecting core sizes to be included. The general considerations that the design of this range of cores is based upon are given in Annex A.

This part of IEC 62317 specifies the standards and existing projects dealing with dimensions
of ferrite cores. It is intended that this standard will include ferrite cores which are widely used and referenced in industry, either because they are included in national standards, or because they are seen to have broad-based use in industry. Where applicable, it is intended that the existing industrial name for each standard part should appear with the part within this series. It is intended that this standard will exclude ferrite cores which are specialty cores with limited use. Also, special cores which are only marginal variations upon standard cores are excluded. Examples: E24/25 (USA) and E24,5 (Metric) are two similar parts, yet they are included separately in this series because they are national standards, widely used.
E-187 (USA) and FEE19A (Japan) are two similar parts, yet they are included
separately in this series because they are national standards, widely used. EP5 has small dimensional differences when comparing different manufacturers, yet only one EP5 is shown in this series, because they are only minor variations on the single basic part. A ferrite core produced by only one or two suppliers may generally be considered a specialty part, and not suitable as a standard core within this series. A ferrite core produced by three or more competing manufacturers may generally be considered to be a candidate to be included in this series. IEC publishes electrical standards for families of ferrite cores, as well as this series of
dimensional standards for families of ferrite cores. Modifications to the ferrite cores listed in
one type of standard should be reflected in the other type.