This part of ISO/TS 13399 is intended to be used for the design of tool layouts for the simulation and the documentation of cutting tool components and cutting tool assemblies. This part of ISO/TS 13399 can be used in connection and correlation with other parts of ISO/TS 13399.The main purpose of this layer structure is the graphical layout of cutting tool components and cutting tool assemblies to be used within tool pre-setting, NC programming and the simulation of processes, as well as for the design of the machining equipment layout.The common concept of the BMG (building model generation) layer structure has been extended with more layer definitions for universal use. This part of ISO/TS 13399 is applicable for a new layout; old, existing data files are not updated to this level. The use of this part of ISO/TS 13399 in terms of change management of existing cutting tool layout is at the manufacturer’s discretion.The extent of the dimensioning is limited to the number of dimensions that are also populated within manufacturer’s or distributer’s catalogues. The manufacturer determines the level of details and is understood as tool specific.As the 3D-simulation systems proceed with stock removal, it is differentiated between cutting and non-cutting tool components. Also, the data concept includes the rules of zero points and mounting points for non-rotating tools (lathe tools).