If this option is disabled, the same tool is used for both the Rough and Finish passes. Enable Use finish tool to create a new tool for finishing. This finishing tool is identical to the tool that was selected for roughing. The name of the new tool is appended with -finish. For example if the roughing tool is named endmill1.0, the finishing tool is called endmill1.0-finish. This finishing tool is not permanently assigned to a tool crib, it is a temporary tool for use in the current document only.