Which two actions should you perform on the milling machine spindles before changing tools?

• A. Raise and Lock
• B. Lower and Unlock
• C. Spin and Secure
• D. Move and Clamp

Answer: (A)

The task tests safe and proper tool-changing setup on a milling machine. You want to create clearance and immobilize the spindle before handling tools. Raising the quill (or spindle) lifts the current tool out of the way so you can remove and install a new one without striking the workpiece or the spindle. Locking the spindle then prevents any accidental rotation or movement while you change tools, protecting you from injury and ensuring the tool seats correctly. Lowering wouldn’t provide the needed clearance, and actions like spinning, moving without locking, or only clamping don’t keep the spindle from turning during the change. So, raising and locking are the correct two actions.