In CNC programming, what best describes tool length?

In CNC programming, what best describes tool length?

• A. Unique offset affecting tool's position on the Z axis
• B. The diameter of the tool tip
• C. The feed rate of the tool
• D. The tool material hardness

Answer: (A)

Tool length is the distance from the machine’s reference surface (often the spindle face or home position) to the tip of the cutting tool, expressed as a tool length offset along the Z axis. In CNC control, each tool can be a different length, so a tool length offset is stored for every tool and applied during machining. When tool length compensation is active, the controller automatically adjusts the Z position so the tool tip reaches the programmed depth, regardless of how long or short the tool is. This lets the same program work with tools of varying lengths without rewriting Z coordinates. A longer tool simply requires a larger offset to reach the same depth, while a shorter tool needs a smaller offset. The diameter, feed rate, and material hardness don’t define tool length; tool length is specifically about the vertical distance to the tip that influences where the cut happens along the Z axis.

Tool length is the distance from the machine’s reference surface (often the spindle face or home position) to the tip of the cutting tool, expressed as a tool length offset along the Z axis. In CNC control, each tool can be a different length, so a tool length offset is stored for every tool and applied during machining. When tool length compensation is active, the controller automatically adjusts the Z position so the tool tip reaches the programmed depth, regardless of how long or short the tool is. This lets the same program work with tools of varying lengths without rewriting Z coordinates. A longer tool simply requires a larger offset to reach the same depth, while a shorter tool needs a smaller offset. The diameter, feed rate, and material hardness don’t define tool length; tool length is specifically about the vertical distance to the tip that influences where the cut happens along the Z axis.