Millwright Level 1 Practice Exam

What does the thread-chasing dial indicate?

1. Tells you when to engage the split nut

2. Indicates the speed of the machine

3. Measures the depth of the cut

4. Shows the amount of coolant used

The correct answer is: Tells you when to engage the split nut

The thread-chasing dial is an important feature in the threading process on a lathe machine. It provides the operator with precise control over the engagement of the split nut, which is a critical component that allows the machine to maintain proper synchronization when cutting threads. Engaging the split nut at the right moment is essential for achieving accurate thread pitch and preventing potential errors in the threading operation. The dial usually consists of graduated markings that help the machinist know the correct point to engage the split nut, ensuring that the lathe's lead screw can accurately follow the desired path for threading. This precision directly affects the quality and consistency of the threads produced. In contrast, other options pertain to functionalities unrelated to the thread-chasing dial. Speed measurement, cut depth, and coolant usage are regulated by other means and do not directly involve the function of the thread-chasing dial, which specifically focuses on thread engagement during the machining process.