Which dial is used to set the depth of cut for external threading on the engine lathe?

Which dial is used to set the depth of cut for external threading on the engine lathe?

• A. Compound feed dial
• B. Diameter knob
• C. Spindle speed dial
• D. Feed rate indicator

Answer: (A)

Setting the depth of cut for external threading is about how far the cutting tool enters the work on each pass. On an engine lathe, that radial movement is controlled most precisely by the compound rest’s feed dial. By turning this dial, you move the tool into the work by a defined amount, which sets how deep each pass cuts the thread. The spindle speed dial adjusts RPM, the diameter knob relates to diameter-related settings, and the feed rate indicator shows longitudinal feed—these affect other aspects of turning but not the per-pass thread depth. So the dial used to set depth of cut during threading is the compound feed dial.

Setting the depth of cut for external threading is about how far the cutting tool enters the work on each pass. On an engine lathe, that radial movement is controlled most precisely by the compound rest’s feed dial. By turning this dial, you move the tool into the work by a defined amount, which sets how deep each pass cuts the thread. The spindle speed dial adjusts RPM, the diameter knob relates to diameter-related settings, and the feed rate indicator shows longitudinal feed—these affect other aspects of turning but not the per-pass thread depth. So the dial used to set depth of cut during threading is the compound feed dial.