Sargent Keso - variation in core design?

[gumptrick]

I was browsing Ebay and noticed there were a couple Sargent Kesos up. Not that strange. But then I noticed that the dimple count in the keys seems to fall into two categories. One has a much higher dimple count than the other. Anyone have any insight on this?

Here are some examples. From my collection; this was an older used lock I got from Ebay:


Screencap from a BosnianBill Youtube video:

Both of those locks have a very high dimple count. You can't see it in the photos, but there are also dimples in the edges of the key.

This is up on Ebay. The lock this key went with looks exactly like the first image I posted above--clearly a used lock.


This is also from Ebay. This lock was bright brass (no plating or other finish) and looked brand new--not a single scratch on it.

...and those two keys have far fewer dimples than the first two.

Any ideas?

[Squelchtone]

AFAIK, the ones with more dimple cuts, I think those are master keys which have all the possible positions drilled for that particular lock system.

[jeffmoss26]

Squelch, you are correct

[mseifert]

I actually lost an auction on Ebay for a Sergent Keso.. and then realize that the guy selling it lives about 10 miles from me..

[gumptrick]

So if I understand things correctly, these locks have a very large number of possible pin locations but only a subset of those are populated in any one given lock?

As a simplified, hypothetical, example: The design might have possible pin locations A through J. One lock might have pins A, C, D, and F used. Another might have B, C, H, J. A master key having positions A, B, C, D, F, H and J (drilled to the correct depth) could open both locks?

[greengrowlocks]

I actually lost an auction on Ebay for a Sergent Keso.. and then realize that the guy selling it lives about 10 miles from me..

Not sure if your looking for a specific form of lock but Security Snobs sells them for $15.00.

[mseifert]

I actually lost an auction on Ebay for a Sergent Keso.. and then realize that the guy selling it lives about 10 miles from me..

Not sure if your looking for a specific form of lock but Security Snobs sells them for $15.00.

usually just looking for something interesting and unique .. Nothing really specific ..

[Evan]

So if I understand things correctly, these locks have a very large number of possible pin locations but only a subset of those are populated in any one given lock?

As a simplified, hypothetical, example: The design might have possible pin locations A through J. One lock might have pins A, C, D, and F used. Another might have B, C, H, J. A master key having positions A, B, C, D, F, H and J (drilled to the correct depth) could open both locks?

@gumptrick:

Yes, the Sargent Keso locks work like the Kaba dimple locks using positional master keying, where the change keys in the system are left uncut in a certain number of positions which are rotated to prevent key interchange. The master keys have all of the cuts. The change keys are prevented from working in locks other than the ones intended because it will have an uncut position on the key which will have a pin providing locking in the cylinders it is not intended to operate.

But there are generally limitations on "parity" in these locks, where the actual pin chambers are drilled in the lock. That being said, that key looks like it has something else going on, those cuts are pretty close together and I would suggest/guess that it is a high level master key in a system which uses cylinders that have sets of five bitting chambers on two different spacings, this is possible as most of the basic dimple keyed locks have several parities to where the pin chambers can be located.

~~ Evan