ISO/TS 13399-304:2016 specifies a concept for the design of tool items, limited to any kind of milling cutters with arbor hole and non-indexable cutting edges, together with the usage of the related properties and domains of values. ISO/TS 13399-304:2016 specifies a common way of design simplified models that contain the following: - definitions and identifications of the design features of milling cutters with arbor hole and non-indexable cutting edges, with an association to the used properties; - definitions and identifications of the internal structure of the 3D model that represents the features and the properties of milling cutters with arbor hole and non-indexable cutting edges. The following are outside the scope of this part of ISO/TS 13399: - applications where these standard data may be stored or referenced; - concept of 3D models for cutting tools; - concept of 3D models for cutting items; - concept of 3D models for other tool items not being described in the scope of this part of ISO/TS 13399; - concept of 3D models for adaptive items; - concept of 3D models for assembly items and auxiliary items.