Understanding Tool Change and Tool Position Points in Five-Axis CNC Machining Centers


Five-axis CNC machining centers are advanced machines used for precise and complex machining tasks. This article aims to explain the concepts of the tool change point and tool position point in these machining centers and how they impact the machining process.

Tool Change Point in Five-Axis CNC Machining Centers:

The tool change point in a five-axis CNC machining center refers to the orientation of the tool holder during automatic indexing. In most cases, the tool change point is selected arbitrarily to avoid interference with the workpiece or fixture during the tool exchange process. However, some machining centers have a fixed tool change point, often chosen near the reference point of the machine or the second reference point.

Tool Position Point in Five-Axis CNC Machining Centers:

The tool position point is a critical reference used for programming, processing, tool setting, and compensation in five-axis CNC machining centers. It defines the characteristics of the tool and varies depending on the type of tool being used:

  1. a) Pointed Turning Tool: The tool point for a pointed turning tool typically refers to the tooltip, which is the sharpest point on the tool’s cutting edge.
  2. b) Arc-Shaped Turning Tool: For an arc-shaped turning tool, the tool point is the center of the arc edge.
  3. c) Forming Tool: The tool point of the forming tool is also usually the tooltip

Tool Compensation in Five-Axis CNC Machining Centers:

The five-axis CNC machining center employs the tangent cut-in method or the standard line cut-in method for tool compensation setup or cancellation. When cutting along the workpiece contour line tangentially or normally is not convenient, an auxiliary block with a transition arc may be added to facilitate the process.

To prevent tool overcutting during the establishment and cancellation of tool radius compensation, it is advisable to position the start and end positions of the program segment on the same side as the compensation direction.


The tool change point and tool position point are crucial aspects of the five-axis CNC machining center. While most machining centers have an arbitrary tool change point to avoid interference, some may have fixed points. Understanding the tool position point helps in programming and setting up the tools accurately. Additionally, utilizing proper tool compensation techniques ensures precise and efficient machining, enhancing the overall performance and capabilities of the five-axis CNC machining center.