Snapped key

A snapped key is one that breaks, almost always inside the lock cylinder, when it is turned hard in a stiff lock or because the key itself is worn. The tip is left inside and the lock can no longer be used.

There is usually a warning first: the key was hard to get in, you had to move the door for it to turn, or the key was bent or cracked. Very worn or poor quality keys snap more often.

If it snaps, do not try to get the piece out with glue or push another key in on top of it: you push the rest further in and the cylinder may be ruined. Keep the part left in your hand. With fine tools it can often be extracted without damaging the cylinder. More under broken key extraction.