Red Seal Machinist Practice Exam

How does a lathe typically create a cylindrical shape?

1. By milling the surface

2. By grinding the edges

3. By rotating the workpiece against a stationary tool

4. By cutting with a rotary drum

The correct answer is: By rotating the workpiece against a stationary tool

A lathe creates a cylindrical shape primarily by rotating the workpiece against a stationary tool. When the material is mounted on the spindle of the lathe, it spins at a specific speed, allowing the cutting tool to engage the surface of the rotating workpiece. As the tool moves linearly along the length of the workpiece, it removes material in a controlled manner, shaping it into the desired cylindrical form. This process is key in machining because the rotation provides uniformity and precision in the shaping of the material. The ability to control the depth and angle of the cut through adjustments to the tool position ensures that the final product meets required specifications for cylindrical dimensions. Other methods mentioned, such as milling, grinding, or cutting with a rotary drum, do not configure the workpiece in the way a lathe does. Milling involves removing material by moving the workpiece past a rotating cutter, which is more commonly used for flat surfaces or specific contours, rather than for producing standard cylindrical shapes.