This part of IEC 60424 gives guidance on allowable limits of surface irregularities of ferrite cores.
This standard is considered as a general specification useful in the negotiation between ferrite core manufacturers and customers about surface irregularities.
IEC 60424-1:1999 history
2015IEC 60424-1:2015 Ferrite cores - Guidelines on the limits of surface irregularities - Part 1: General specification
1999IEC 60424-1:1999 Ferrite cores - Guide on the limits of surface irregularities - Part 1: General specification
IEC 60424-1:1999 Ferrite cores - Guide on the limits of surface irregularities - Part 1: General specification has been changed from IEC 60424:1973 Guide to the specification of limits for physical imperfections of parts made from magnetic oxides.