what do you call a padlock that takes 2 keys to open

[Donnie]

Hi team, I have a padlock that will open with either of 2 keys,one is marked "master" & the other is marked "change"...Am I correct to call this a BICENTRIC lock?
I AM LOOKING FOR A LOCK THAT TAKES 2 KEY'S TO OPEN IT>>

What is THAT lock referred to in name.....for my search?..........thank you, Donnie

[Tom Gordon]

A bicentric lock has two keyholes - each keyhole has a different key and either key, in it's own keyhole, will open the lock.
A masterkeyed lock has one keyhole but two differnt keys can open the lock.

[Donnie]

Did Yale not make a padlock that takes 2 keys to open it ? Sort of like a safe deposit box?
Maybe I'm wrong in my thought process'....but I thought that they did...Donnie

Tom, thanks for your response

[Tom Gordon]

You can see that it would be difficult to use both keys at the same time.

[Donnie]

Tom, I can see that it would be difficult to turn both key's at the same time, but you could turn 1 & then the other, not at the same time...I guess I must be mistaken....
I'm not sure where I got this notion from, but you are telling me that no such lock exists or ever did, correct?

The 2 types that you mentioned are the only styles made....yes???
I ask because a friend has a lock with 2 keyway's & no keys
This is then a bicentric lock like I already have, and his lock can then be opened with 1 key from either keyway, correct?
His lock is older than mine(trefoil) before 1928 as I understand..that is why I like it, but it may be to costly to have key's made for it......I'm a collector & not a locksmith
Thank you for reading my post & answering my question's........Donnie

[Tom Gordon]

I havent seen a whacking great padlock that needed both keys turned at the same time, but there are more padlocks used in America than over here and maybe there is a government or financial institution that decided it wanted to set up a system where it employed two keyholders who were required to be there in order to operate a low security lock like a padlock (which by definition cannot be as secure as a mortice lock.)
The right locksmith could read the mechanism by eye and cut the key to code or impression keys.

[Pschiffe]

The bicentric padlocks were apparently made in two versions, one for masterkeyed applications where either key would open the padlock. The other, which is exceedingly rare; was for dual custody situations where both keys were required to open the lock. See this thread for more:
http://www.antique-locks.com/showthr...entric-padlock

Pete Schifferli

[Adrian Weber]

Isn't the bicentric padlock explained in the padlock handbook?
I am not sure though but will take a look as soon as I am home again withing the next days :)

[Pschiffe]

Isn't the bicentric padlock explained in the padlock handbook?
I am not sure though but will take a look as soon as I am home again withing the next days :)

Not found in Padlock Handbook, copyright 1970 by Locksmith Ledger.

Pete Schifferli

[wylk]

Back to being serious, do these padlocks have anti-rapping design features? Are they inherently resistant? Or, are they a poor design from this standpoint?