The engine to select tools is quite complex and provides a unpaired flexibility.
The restrictions are Boolean conditions that are verified. If accepted (true), the tool passes that restriction and can be considered a candidate to a determined operation. This restriction verifies if the machining diameter matches the value set by the customer. If it does the tool is a candidate to be used, if not, the tool is discarded.
This restriction rejects the tool based on the inside diameter of the material. If the material exceeds a determined amount – user set – the tool is not accepted, and therefor discarded for the current operation.
More information on the tool management settings: Tool management – Definitions