IEC 63093-7:2018(E) 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 first edition cancels and replaces the first edition of IEC 62317-7 published in 2005. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to IEC 62317-7:a) IEC 63093-7 integrates IEC 62317-7 and IEC 60424-3;b) IEC 60424-3:2015, Table 2, has been included in Annex C as Table C.1.