What is the main function of a lathe in manufacturing?

The primary function of a lathe in manufacturing is to create cylindrical shapes. Lathes operate by rotating a workpiece against a cutting tool, which removes material to shape the workpiece into a desired cylindrical form. This capability makes lathes incredibly versatile for producing various components such as shafts, pins, and other rotationally symmetric parts.

In contrast, options related to cutting flat surfaces, welding, and casting pertain to different manufacturing processes. Cutting flat surfaces typically involves milling or grinding, welding is a process for joining materials, and casting involves pouring molten metal into a mold to create a specific form. Each of these processes has its distinct machinery and techniques, highlighting the unique role that lathes play in the realm of metal cutting and shaping operations.