When should the lathe chuck key be removed from the spindle?

• A. After clamping the tool securely
• B. After selecting the appropriate speed
• C. After the automatic feed is enabled
• D. After clamping the workpiece

Answer: (D)

Never leave a chuck key in the chuck once you’ve tightened the workpiece. The key is used to tighten the chuck jaws around the workpiece, so after you’ve clamped it securely you must remove the key before starting the spindle. Leaving the key in place poses a serious safety risk: once the chuck spins, the key can be grabbed, ejected, and potentially cause injury or damage. The other steps (setting speed or enabling automatic feed) aren’t the moment to remove the key—the key should come out right after clamping the workpiece and before spinning the lathe.