Common Room Keying

[cledry]

Just a quick point. A Kwikset master key system can be much larger than a Schlage system despite the Kwikset having a lesser number of depths. We only master key Kwikset locks for the local housing authority and the system is huge! Couldn't get anywhere near the number of changes with a Schlage.

Why would this be? Presumablw with Kwikset all 7 depths can be used whereas with Schlage presumably adjacent depths are so small that only alternate depths can be used.
Seems that in general only 5 depths can be used for masterkeying in a normal 10 depth cylinder, hence some manufacturers seem to have moved to 6 depth cylinders where all 6 depths can be used for masterkeying thus increasing the potential system size.

Old thread, but yes, it is just as you describe.

[GWiens2001]

However, if you take a 6 pin Schlage cylinder and key it to Kwikset depths, you get a phenomenal system size.

If you use the 6 pin depths for Kwikset in a 6 pin Schlage cylinder, you have 16,807 differs. If you use the 7 pin depths for Kwikset, you end up having 117,649 differs.

Schlage 6 pin cylinder with 2 step master keying gives 15,625.

I believe that is about correct, though it does not take MACS into consideration.

Gordon

[Evan]

However, if you take a 6 pin Schlage cylinder and key it to Kwikset depths, you get a phenomenal system size.

If you use the 6 pin depths for Kwikset in a 6 pin Schlage cylinder, you have 16,807 differs. If you use the 7 pin depths for Kwikset, you end up having 117,649 differs.

Schlage 6 pin cylinder with 2 step master keying gives 15,625.

I believe that is about correct, though it does not take MACS into consideration.

Gordon

@Gordon:

I have heard of this being done before but only ever seen knock off brand hardware using the SC1 keyway with Kwikset type pins.

Here are a couple of problems:

You can not use the # 7 depth unless you have two pins in the stack as Kwikset does not make # 7 pins. This would create issues with the use of the only safe way to master key Kwikset locks using the rotating constant method as you would not be able to use # 7 as a constant position depth. This would reduce the available keyspace by one bitting for each of the constant chambers used.

Theoretical possible changes: 7 x 7 x 7 x 7 x 7 x 7 = 117,649

Let's say you use a 3-in-6 Rotating Constant master keying system: 7 x 7 x 7 x 6 x 6 x 6 = 74,088

You would then have to figure out how MACS would work, how many combinations would be lost and which type of pins you would use to accomplish this system. Would you use the Schlage type pins (possibly Lab pins in the new sizes needed) or Kwikset type pins which would be subject to the issue described above? This would also dictate how you must cut the keys being used.

One thing you have to worry about when master keying Kwikset is that they are a common lock type and random keys from the outside world will have a greater likelihood of operating the locks if you use Total Position Progression as your master keying method. This is why bitting parity is a thing, the pattern of Odd and Even cuts for a two-step master key system. OEOEOE OOEEOE EEOOOE etc.

Schlage 6 pin cylinder with 2 step master keying gives 15,625.

This would be the total available keyspace. When you factor in a typical TPP master key system the number of changes after selecting the TMK becomes 4,096 changes.

Not saying these are impossible things to overcome, but it would be totally custom work and would not be terribly practical.

~~ Evan

[billdeserthills]

Gordon didn't say anything about using Kwikset pins, only Kwikset depths