IEC 60401-1:2020 pdf free.Terms and nomenclature for cores made of magnetically soft ferrites-Terms used for physical irregularities and reference of dimensions.
Physical irregularities mean here the surface irregularities，bulk irregularities and shapeirregularities.The irregularity here stands for inconsistency of the state or quality of the part’ssurface, bulk or shape with its intended regularity.These irregularities are considered here inthe macroscopic scale， i.e. within the range of linear dimensions of irregularities from onemicrometre to tens of millimetres.
There is a great variety of surface, bulk and shape irregularities degrading the quality of partsmade of ferrites. Different types of these irregularities can often occur together and overlapone another.
Each type of irregularity is，in general，produced by one or more of the following: processvariability in a manufacturing step, handling, grinding, packing or transportation.
The extent of the quality degradation is dependent on the type, scale, and combination ofirregularities being present as well as on their locations on the part. There are locationsparticularly sensitive to the degrading effect of the specific types of irregularities.
The irregularities can in extreme cases have a detrimental or critical effect on magnetic,electric and mechanical performances of the part.Operations performed on the part, such asmarking，winding，assembling and mounting，can also be adversely affected by theirregularities.
An ongoing tendency to upgrade the overall quality of the parts results in more stringentrestrictions being imposed on the quantity of irregularities in these parts.
This brings about a need for a set of definitions, or nomenclature,which would be a primarybasis for approaches to irregularities and their location issues.
Therefore, this nomenclature is intended to be used as a uniform reference when formulatingmore detailed descriptions of irregularities at specified locations，requirements andprocedures related to the inspection and assessment of irregularities. This nomenclature canalso be useful with regard to methods and tools used for detection，recognition andclassification of irregularities.
surface irregularity unintentional state or appearance of the surfaces,edges and corners of the part.
interior irregularity unintentional inhomogeneity inside the part.
shape irregularity unintentional deformation of the contour lines or surfaces delimiting the shape of the part.IEC 60401-1 pdf download.