What is the difference between turning and milling operations?

Turning and milling are two distinct machining processes used to create parts, and the difference fundamentally lies in how they operate with respect to the workpiece and the cutting tool. In turning operations, the workpiece is secured and rotated against a stationary cutting tool, which removes material to create cylindrical shapes. This process is commonly used for producing parts like shafts or pins.

On the other hand, milling involves the rotation of the cutting tool while the workpiece remains stationary or moves in multiple axes. This allows for a variety of cuts and profiles to be made in flat or contoured surfaces, which makes milling versatile for creating more complex shapes and features.

The other options highlight certain aspects but do not accurately characterize the essential differences in how the processes work. For instance, stating that turning results in cylindrical shapes while milling results in flat surfaces captures some results of the operations but does not explain the mechanics involved. The correct choice clarifies the fundamental operational differences that set turning apart from milling.