IEC 63093-11:2018(E) 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 first edition cancels and replaces the first edition of IEC 62317-11 published in 2015 and the second edition of IEC 60424-3 published in 2015. This edition constitutes a technical revision.   
This document includes the following significant technical changes with respect to IEC 62317­11:2015 and IEC 60424-3:2015:

1. This document integrates IEC 62317-11:2015 and IEC 60424­3:2015;
2. Table 3 – Allowable areas of chips for EC-cores, of IEC 60424-3:2015, has been moved to Annex B (informative) of this document.