Which machining operation would you use to cut threads onto a cylindrical workpiece?

Turning is the correct operation for cutting threads onto a cylindrical workpiece because it involves rotating the workpiece against a cutting tool. This process allows for precise control over the shape and size of the thread being created. In turning, the cutting tool moves linearly along the length of the workpiece while the workpiece spins, enabling the formation of helical grooves that characterize threaded surfaces.

The other options do not suit this specific task. Pocket milling is used for cutting cavities or pockets into a surface and is not designed for threading. Profiling refers to shaping the outline of a part and typically does not involve creating threads. Drilling is intended for creating holes and would not accommodate the helical nature of thread cutting. Therefore, turning stands out as the applicable operation for this machining requirement.