Which of the following statements about chuck keys is correct?

• A. The chuck key should be kept in the chuck after clamping the tool
• B. The chuck key should be removed from the chuck when not actively clamping a tool
• C. The chuck key should be left near the machine
• D. The chuck key has no safety impact

Answer: (B)

Safety with chuck keys is about preventing injury from a moving machine. The best practice is to remove the chuck key from the chuck when you’re not actively using it to clamp a tool. If the machine starts or the chuck spins while a key is left in the jaws, the key can be driven outward at high speed, acting like a projectile that can strike you or others and cause serious injury. Keeping the key out of the chuck and storing it in a designated location eliminates this risk and helps ensure the tool is clamped properly without accidental interference.

Leaving a key in the chuck after clamping is unsafe because it can still be caught or cause damage if the chuck or tool moves. Having the key lying around near the machine creates a tripping or snag hazard and does not prevent the key from becoming a hazard if the machine starts unexpectedly. And since a chuck key has a direct safety impact in preventing injuries, saying it has no safety impact isn’t accurate.