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 grew up with Segal Slam Locks. The large locking mechanism inside a door where the bolt drops vertically.
I see other companies selling them and if I am looking for one, what do I call it?
Do I call it a Vertical Deadbolt? A Drop Lock? A Jimmy Proof Lock? A Slam Lock?
I’m wondering if there is such a thing as a combination padlock, that you can lock without the correct code being set? In the sense you can lock a keyed padlock without the key, so that for example I could leave the padlock open for someone else to finish up with something and then just tell them to snap it closed when they were done. Could get a keyed lock, but my bunch is already too big and ideally don’t want to carry 2 bunches of keys around
Thanks in advance