Final answer:
The tool bit on a lathe should be positioned at the centerline of the workpiece to ensure accurate and efficient cutting, with adjustments made based on the material and operation being performed.
Step-by-step explanation:
While operating on a lathe, the position of the tool bit is critical for effective machining. The tool bit should be positioned at the centerline of the workpiece to ensure proper cutting action. If the tool is too high or too low, it may cause improper cutting, leading to inaccuracies and possible damage to both the tool and workpiece.
Furthermore, ensuring the tool is at the right angle and securely fastened can improve cutting efficiency and the quality of the finished product. It is also important to adjust the tool bit according to the specific material being cut and the desired operation, such as turning, facing, or knurling.