Which task can a mill perform in machining?

A mill is primarily used for cutting and shaping a workpiece, which involves the removal of material from a solid block to create the desired shape and features. This process can include creating flat surfaces, grooves, slots, and complex contoured surfaces, typically using a rotating cutting tool.

While drilling holes in a metal surface is indeed possible with a milling machine, the core function of a mill goes beyond that singular task to include versatile shaping capabilities. On the other hand, sanding wood surfaces and welding metal pieces together are not functions performed by a mill; sanding is typically associated with finishing processes for wood materials, while welding involves joining metals through melting and fusing, which requires different equipment. Hence, the characteristic ability of a mill to cut and shape a workpiece makes it the most fitting answer.