IEC 63182-8:2025
(Main)Magnetic powder cores - Guidelines on dimensions and the limits of surface irregularities - Part 8: U-cores
Magnetic powder cores - Guidelines on dimensions and the limits of surface irregularities - Part 8: U-cores
IEC 63182-8:2025 specifies the dimensions that are of importance for mechanical interchangeability for a preferred range of U-cores made of metallic magnetic powder and gives guidelines on allowable limits of surface irregularities applicable to U-cores.
This document is a specification that is useful in the negotiations between magnetic powder core manufacturers and customers about surface irregularities.
The use of "derived" standards which give more detailed specifications of component parts while still permitting conformance with this document is discussed in Annex A.
General Information
Standards Content (Sample)
IEC 63182-8 ®
Edition 1.0 2025-08
INTERNATIONAL
STANDARD
Magnetic powder cores - Guidelines on dimensions and the limits of surface
irregularities -
Part 8: U-cores
ICS 29.100.10 ISBN 978-2-8327-0668-8
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CONTENTS
FOREWORD . 2
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Primary dimensions . 4
4.1 General . 4
4.2 Dimensions of U-cores . 4
4.2.1 Main dimensions . 4
4.2.2 Effective parameter . 6
5 Limits of surface irregularities . 6
5.1 General . 6
5.2 Examples of surface irregularities . 6
5.3 Chips and ragged edges . 7
5.3.1 General. 7
5.3.2 Chips and ragged edges of mating surfaces. 7
5.3.3 Chips and ragged edges on the other surfaces. 7
5.4 Cracks . 8
5.5 Flash . 8
5.6 Rust . 9
5.7 Discoloration . 9
Annex A (informative) Derived standards . 10
Figure 1 – Main dimensions of U-cores . 5
Figure 2 – Examples of surface irregularities . 7
Figure 3 – Locations of chips and ragged edges for U-cores . 7
Figure 4 – Locations of cracks for U-cores . 8
Figure 5 – Locations of flashes for U-cores . 8
Figure 6 – Locations of rust for U-cores . 9
Table 1 – Main dimensions of U-cores . 5
Table 2 – Effective parameter . 6
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Magnetic powder cores -
Guidelines on dimensions and the limits of surface irregularities -
Part 8: U-cores
FOREWORD
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IEC 63182-8 has been prepared by IEC technical committee 51: Magnetic components, ferrite
and magnetic powder materials. It is an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
51/1562/FDIS 51/1578/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 63182 series, published under the general title Magnetic powder
cores – Guidelines on dimensions and the limits of surface irregularities, can be found on the
IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
1 Scope
This part of IEC 63182 specifies the dimensions that are of importance for mechanical
interchangeability for a preferred range of U-cores made of metallic magnetic powder and gives
guidelines on allowable limits of surface irregularities applicable to U-cores.
This document is a specification that is useful in the negotiations between magnetic powder
core suppliers and users about surface irregularities.
The use of "derived" standards which give more detailed specifications of component parts
while still permitting conformance with this document is discussed in Annex A.
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.
IEC 60205, Calculation of effective parameters of magnetic piece parts
IEC 63182-1, Magnetic powder cores – Guidelines on dimensions and the limits of surface
irregularities – Part 1: General specification
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 63182-1 apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
– IEC Electropedia: available at https://www.electropedia.org/
– ISO Online browsing platform: available at https://www.iso.org/obp
4 Primary dimensions
4.1 General
Conformance with the requirements of 4.2 ensures mechanical interchangeability of complete
assemblies and coil formers.
4.2 Dimensions of U-cores
4.2.1 Main dimensions
The main dimensions of U-cores with rectangular cross-section shall be those given in Table 1.
The dimensions specified in Table 1 are illustrated in Figure 1.
Figure 1 – Main dimensions of U-cores
Table 1 – Main dimensions of U-cores
A B C D E L
a
mm mm mm mm mm mm
Size
Min. Max. Min. Max. Min. Max. Min. Max. Min. Min. Max.
U35/36/20 34,5 35,5 35,5 36,5 19,5 20,5 24,9 25,1 12,4 10,8 11,2
U35/36/25 34,5 35,5 35,5 36,5 24,5 25,5 24,9 25,1 12,4 10,8 11,2
U41/41/20 40,4 41,6 40,4 41,6 19,5 20,5 27,9 28,1 14,4 12,7 13,3
U41/41/25 40,4 41,6 40,4 41,6 24,5 25,5 27,9 28,1 14,4 12,7 13,3
U41/41/30 40,4 41,6 40,4 41,6 29,5 30,5 27,9 28,1 14,4 12,7 13,3
U52/51/25 51,3 52,7 50,3 51,7 24,5 25,5 34,8 35,2 19,2 15,7 16,3
U52/51/30 51,3 52,7 50,3 51,7 29,5 30,5 34,8 35,2 19,2 15,7 16,3
U55/28/16 54,2 55,5 27,1 28,1 15,9 16,7 16,7 17,5 32,5 10,3 10,7
U55/28/23 54,2 55,5 27,1 28,1 22,8 23,6 16,7 17,5 32,5 10,3 10,7
U63/61/30 62,2 63,8 59,7 61,3 29,5 30,5 41,3 41,7 24,0 18,6 19,4
U63/61/35 62,2 63,8 59,7 61,3 34,5 35,5 41,3 41,7 24,0 18,6 19,4
U65/33/20 64,4 66,0 32,0 33,0 19,6 20,4 19,6 20,4 38,5 12,3 12,8
U65/33/27 64,4 66,0 32,0 33,0 26,6 27,4 22,1 22.9 43,3 9,8 10,2
U72/36/21 71,5 73,3 34,9 36,2 20,5 21,3 21,3 22,1 42,8 13,6 14,2
U79/65/30 78,0 80,0 63,5 65,5 29,5 30,5 42,3 42,7 33,6 21,6 22,4
U79/65/35 78,0 80,0 63,5 65,5 34,5 35,5 42,3 42,7 33,6 21,6 22,4
U80/38/20 79,1 80,9 37,5 38,7 19,4 20,2 28,1 28,3 5
...
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