IEC 63093-5:2025

IEC 63093-5 ®
Edition 2.0 2025-12
INTERNATIONAL
STANDARD
Ferrite cores - Guidelines on dimensions and the limits of surface irregularities -
Part 5: EP-cores and associated parts for use in inductors and transformers
ICS 29.100.10  ISBN 978-2-8327-0907-8

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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 EP-cores . 5
4.2.1 Principal dimensions . 5
4.2.2 Effective parameter and A values . 5
min
4.3 Dimensional limits for coil formers . 6
4.4 Pin locations and base outlines . 7
5 Limits of surface irregularities . 8
5.1 General . 8
5.2 Examples of surface irregularities . 9
5.3 Chips and ragged edges . 9
5.3.1 General . 9
5.3.2 Chips and ragged edges on the mating surfaces . 9
5.3.3 Chips and ragged edges on the other surfaces . 10
5.4 Cracks . 12
5.5 Flash . 12
5.6 Pull-outs . 12
5.7 Crystallites . 13
5.8 Pores . 14
Annex A (informative) EP-core design. 15
A.1 General . 15
A.2 Pin location and base outlines . 15

Figure 1 – Principal dimensions of EP-cores . 5
Figure 2 – Main dimensions of coil formers for EP-cores . 6
Figure 3 – Pin locations (SMD type) viewed from the upper side of the board . 7
Figure 4 – Pin locations (PTH type) viewed from the underside of the board . 8
Figure 5 – Examples of surface irregularities . 9
Figure 6 – Chip and ragged edge location for EP-cores . 10
Figure 7 – Crack flash and pull-out locations for EP-cores . 12
Figure 8 – Crystallite location for EP-cores . 13
Figure 9 – Pore location for EP-cores . 14

Table 1 – Principal dimensions of EP-cores . 5
Table 2 – Effective parameter and A values . 6
min
Table 3 – Dimensional limits for coil formers for EP-cores. 6
Table 4 – Area and length reference for visual inspection . 11
Table 5 – Limits for cracks . 13

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Ferrite cores - Guidelines on dimensions
and the limits of surface irregularities -
Part 5: EP-cores and associated parts
for use in inductors and transformers

FOREWORD
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IEC 63093-5 has been prepared by IEC technical committee 51: Magnetic components, ferrite
and magnetic powder materials. It is an International Standard.
This second edition cancels and replaces the first edition published in 2018. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) revision of Table 2 according to IEC 60205:2016.
The text of this International Standard is based on the following documents:
Draft Report on voting
51/1580/FDIS 51/15
...