Rotating tools rapidly remove material, which is attached to a moving stage and is computer controlled. Which machine is described?

• A. CNC lathe
• B. CNC milling machine
• C. CNC router
• D. Punching machines

Answer: (B)

Rotating cutting tools remove material while the workpiece is carried on a CNC-controlled stage. This setup—a rotating cutter doing the cutting as the table (the stage) moves under computer control—defines a CNC milling machine. Milling uses a spinning cutter to shape the workpiece, typically with multi-axis movement of the table and sometimes the spindle for precise removal.

A CNC lathe operates differently: the workpiece itself spins, and the tool mostly moves in and out to cut, so rotation happens with the workpiece, not the cutting tool. A CNC router is similar in principle to milling but is usually used for softer materials like wood or plastics. Punching machines remove material by punching holes or shapes rather than using a rotating cutting tool.