What is the primary purpose of a lathe?

The primary purpose of a lathe is to shape materials into specific forms. Lathes are versatile machining tools that rotate a workpiece against various cutting tools to create cylindrical shapes, threads, and other geometrical features by removing material. This process involves the workpiece being securely held in the spindle while the cutting tool is fed against it, allowing for precise shaping and finishing operations.

The other options refer to distinct processes or equipment that serve different functions within the field of machining and metalworking. For example, heating metals for treatment or melting materials for casting are processes that typically involve furnaces or ovens, not lathes. Similarly, measuring the precision of a workpiece is handled by measuring instruments rather than a lathe, which is focused on the act of shaping material. Thus, the lathe’s fundamental role is fundamentally about forming materials, making the first choice the correct answer.