The concept of tool radius compensation is similar to the use of tool length compensation. When programming, there is basically no need to consider the length of the tool. With tool radius compensation, we can avoid considering too many tool diameter sizes. Tool length compensation is applicable to all tools, while tool radius compensation is generally only used for milling cutters. When milling the outer or inner surface of a workpiece, cutter radius compensation is used. When machining the end face of a workpiece with a end face milling cutter, only tool length compensation is required. Due to the fact that tool radius compensation is a relatively difficult instruction to understand and apply, many people refuse to use it in programming. But once we understand and master it, it will bring great convenience to our programming and processing when applied.