| submitted by /u/Odd-Nobody-1466
With pin tumbler locks, no. They have two completely separate cylinders in North America, and two separate plugs in the same cylinder in Europe (typically). There are no connections between both save for the meshing of cams and such. That means that a key inserted inside does not even reach the tip of where the outside key goes.
In North America, leaving a key inside does not usually prevent someone from using a key outside. I have a double cylinder deadbolt on my house door and typically always leave a key in the inside cylinder and it does not affect the operation of the outside cylinder. If I had the inside key on a heavy ring of keys, maybe, but I doubt.
In Europe (with profile cylinders), leaving a key inside, if it is turned, will prevent the outside cylinder from operating because the cam will not be lined up correctly to permit the outside plug to work.
If you’re talking about the rather inexpensive mortise locks that use a bit key, those share the same mechanism for inside and outside, and it can be done provided the inside key is in the neutral position. If the inside key has been turned, then you must turn it back to neutral before pushing it in further to make room for the outside key. These locks don’t have the keyhole in the lever, but on the door usually below the lever (or knob).
I feel like the risk of that actually happening is pretty low. The few that possess that skill with consistency are locksmiths…. I don’t know common criminals that have this skill in addition to having key blanks and a cutter, the wherewithal to slog through all of his posts and narrow it down to a place and then go to his house and use that key to unlock it. Seeeeeems like a stretch to me. Not to mention there’s another key in that photo with the actual code stamped on the face… even then it’s still a stretch.
It’s a defiant lock… so it’s not like the lock was an impenetrable fortress to begin with.
These camlocks are pretty cheap. The one you have there is referred to where I am from as a gem lock (Ace is some places) Chicago is my go to manufacturer for cutting keys to code. 7 pins in a radial fashion. If you really want to pull it apart, remove that brass plug in the middle of the housing. I find it easiest to drill a hole in the middle of the plug, force a cam screw into the hole and then lever it out with a set of side cutters. Shit will go everywhere. I give these to my 1st year apprentices for some character building. Locks sell for about 8 dollars. We only disassemble and rekey these if they have 50+ locks. Key will only be removed in one or two positions depending on how many cut aways it has for the notch on the key.
i’m guessing that a pin dropped and the cylinder is now stuck halfway out. take a picture of the top of the lock. we want to see whats keeping the pins in place.
but anyways its a cam lock, it works as a override on the safe if they forget the combo or if the batteries die. you should be able to replace it with any similar length cam lock.