Red Seal Machinist Practice Exam

How do turning and milling operations differ?

1. Turning uses a stationary workpiece, milling rotates the workpiece

2. Turning shapes material using a rotating workpiece, milling uses a rotating cutting tool

3. Milling is slower than turning

4. Turning is only used for metals, milling is used for plastics

The correct answer is: Turning shapes material using a rotating workpiece, milling uses a rotating cutting tool

Turning and milling operations differ primarily in how they interact with the workpiece and the cutting tool. In turning operations, the workpiece is held stationary while it rotates against a stationary cutting tool, which removes material to create a cylindrical shape. This process is particularly effective for producing parts like shafts and rings. Conversely, in milling operations, the cutting tool is the component that rotates, and the workpiece remains fixed, or it may move relative to the tool. Milling can create a variety of shapes, including flat surfaces, grooves, and complex profiles, depending on the tool's design and movement. Thus, the correct answer highlights this fundamental distinction: turning involves a rotating workpiece and a stationary tool, while milling involves a rotating cutting tool with the workpiece potentially remaining still or moving. This understanding is crucial for machinists when selecting the appropriate machining operation based on the part's design and material requirements.