What does the G84 command indicate?

The G84 command specifically indicates a tapping cycle in CNC programming. This command is used to perform tapping operations, which involves creating internal threads in a workpiece through rotational motion and linear advancement of the tool into the material. Tapping cycles help automate the process, allowing the machine to control the feed and retract of the tap in a coordinated manner, thus enhancing precision and efficiency in thread creation.

The context of other options highlights that while drilling cycles (A) and milling cycles (C) involve creating holes and shaping materials respectively, they utilize different G-code commands. The purpose of sanding cycles (D) is unrelated to CNC machining processes as they are more relevant in surface finishing tasks, rather than cutting or forming operations.