master key system help

[shutterstuff]

Ok, I have done basic master key systems by hand and recently purchased software to do this faster and to eliminate math issues. But I have a need for a key I think is called a "key to pass". Small 12 unit apartment building, 1 GM for the Knox Box, 1 master for the owner and manager and 12 change keys. What we need is all keys to open the door to the laundry room without having a 2nd key. Math is not my strong point and the software (Areo Key from CLK) does not do this. I know I will need to stack multiple master pins, but figuring out the pinning is driving me nuts. Any suggestion other than HPC's Master King software (on my wish list already)?

[jeffmoss26]

The term I have always heard is 'maison keying' hope that helps a bit in your search!

[shutterstuff]

Thanks Jeff! That helped, I am getting this project done by trial and error. I need to do the install this week.

[cledry]

Talk them out of it if possible, unless it is a restricted keyway. Try to talk them into a combination lock. Maison keying is never a good idea. What brand of lock are you dealing with?

[shutterstuff]

Talk them out of it if possible, unless it is a restricted keyway. Try to talk them into a combination lock. Maison keying is never a good idea. What brand of lock are you dealing with?

Hi Jim, After doing more research Security is a common issue. I am actually about to do what you say on one of the two jobs. The laundry room does not need to be that secure. But the other job is a church. They are just going to have to use 2 keys for everyone not carrying a master (pastors and full time staff).

Thanks all for the help. the Maison term was what I needed to research this out more.

[peterwn]

Ok, I have done basic master key systems by hand and recently purchased software to do this faster and to eliminate math issues. But I have a need for a key I think is called a "key to pass". Small 12 unit apartment building, 1 GM for the Knox Box, 1 master for the owner and manager and 12 change keys. What we need is all keys to open the door to the laundry room without having a 2nd key. Math is not my strong point and the software (Areo Key from CLK) does not do this. I know I will need to stack multiple master pins, but figuring out the pinning is driving me nuts. Any suggestion other than HPC's Master King software (on my wish list already)?

I think 'key to pass' means 'keyed alike' and hence a 'pass key' means a key to fit a set of keyed alike locks. Heard the term used for master keys but that seems wrong.

[shutterstuff]

I think 'key to pass' means 'keyed alike' and hence a 'pass key' means a key to fit a set of keyed alike locks. Heard the term used for master keys but that seems wrong.

The maison term was what I was referring to. Both jobs are done and almost everyone is happy. Only the people that have to carry an extra key we disappointed.

Thanks to everyone that helped! I was not aware that Maison keying was such a security risk.

[Sinifar]

Master keying is the controlled destruction of security. Having said that -- when one designs a master key system - you should know in advance that you will need "common" keyed doors. These should not be wafered up with tons of .025 or .030 master pins, but should be something else. what will make your system secure is LESS master pins in the locks, not more.

So you should have at least two, and for a system this small three pins in the set, common.

How many changes do you really need? Go back to the "magic Square" and start working the thing by hand.

10110
32332
54554
76776
98998

Okay now you have the square. Start by "X" ing out the mast cuts. Say 36514. Okay that is your master. now the change keys?

You do not want to use the master cuts on the changes keys except for the common cuts. So ... To avoid a lot of wear, use the master first cut as one of the common cuts -- 3.

Next, work out the load block, this is all the cuts in order which are not masters, so the first chamber is out, but two thru five are in -- well, you should have a second common cut, so pick the last one, 4. Now remember the MACS, and don't go off with super wide splits between cuts.

Now you have a matrix of 3XXX4 for the common keying, add one more and you have it. The "X" on this case is no pins in the chamber.

Your load block should look something like this -

013
033
043
063
213
233
235
237
239
413
433
435
437
439
833
835
837
839

Okay that is the start, you can progress this further by following that pattern. This gives you 18 change keys. Now why did I do it this way? That 3 in the middle can be another common cut. So in the end, the common locks are loaded 3X (1/3) X 4. this keeps the locks from being wafered up. It also gives a good wide variety of cuts. Now load them "shotgun" that is randomly pick off the list the keys which are cut, and leave gaps between each - so that one apartment cannot go down the hall and figure that his is "413" and the next one is "433" - when it works out to be "835" and the next one to either side is "239" - "433" .. now you get it and how to do it.

I know long, but a lesson in MK work which most do not get.

Questions? Ask me.

Sinifar

[GWiens2001]

Very nicely explained, Sinifar.

Gordon

[Robotnik]

Agreed. Even being familiar with the principles of master keying, I've never heard the process explained so clearly. Thanks for this.

[jeffmoss26]

can you explain the 'magic square' ?
Thanks!

[Sinifar]

The "magic square" is the base for pencil and paper master key systems. It gives you a block of number to work from in which you have laid out before you all the number used in the system. You choose odd or even as the numbers march across the square. Remember the MACS (Maximum Adjacent Cut Specification) so as to not destroy your pin land. That flat that the pin nose sits on. HOWEVER -- there are "MACS stretchers" which decrease the angle of the ramp between cuts and you can exceed the MACS if you use that trick. Using a Sargent cutter for example is one way of doing it. (80 degrees) But know keys will pull and push in and out harder using this trick. SO use it sparingly. When ever I do that I make a note on the sheet that I have used it for THAT key ONLY.

SFIC (BEST) does not have a MACS due to the .012 drop between cuts, and the extreme accuracy needed to work the cores.

You cross off the numbers used for the master, and then can start to list the rotator cuts in order, as I did above. For larger systems you need to either reserve another cut for a GM or higher, or go to a 6 pin system and the work is pretty much the same thing, except one of the cuts ends up being the master determinator.

So, in the example, you got originally 3XXX4 and now to make another MK / GMK you would need to add one more column of numbers so in this case I chose to make the thing the 6th pin, and it becomes - /1 - 3 - 5 - 7 - 9 / With one of those as the GM say, 3, and the Master being say 7. Now your keys would be for the first system 3XXX47. The "XXX" is the rotators.

In big systems always note where your thing is going and try to make MK / GMK numbers at least 4 or .060 apart if they are close. I know that can be hard but do it. It keeps close keys from "jiggling" the thing open. Also always use a shotgun loading. As I said above, work out your usable cuts, remembering the MACS, and use the trick of grouping your numbers for common keying, as I showed above.

In an apartment building use one group for each building so that the common keys do not interchange.

A common key could be cut as this - 3X3X4, and that would only operate the common locks for a meter reader, paper boy, garbage man, or what have you. Use any "off time" cut for the missing X cuts or just leave it as an uncut key. Most '0" cuts are something, and some are pretty big like Arrow, so this trick will work as well.

Hope that helps

Sinifar

[jeffmoss26]

I appreciate the info as always!

[shutterstuff]

Sinifar, thanks for your explanation!

My mentor learned many years before computers and his system is different than what you showed. But your explanation made it even clearer.

[GWiens2001]

There are a number of systems out there. But from the little I know about master keying, most start with the basic information about which Sinifar spoke, then use varying methods of deciding Master and Change keys.

Sinifar's method is probably the best and most reliable method of which I am aware.

Gordon