Master Keying Systems

[SoMotivated10]

So I am studying Locksmithing and I am so lost feeling on Master Key Systems. .

I am having trouble understanding Master key bitting charts and how to come up with bitting combinations for change keys..

Can anyone simplify this for me in some way? If you need additional information I will provide. .

Thanks

[Evan]

@SoMotivated10:

First lets consider the basics of masterkeying:

Your system design will be impacted by the following factors:


• The type of lock and bitting system in use
• The size of the system needed and the number of pin chambers in the cylinders
• The levels of keying and complexity required within the master key heirarchy
• The amount of cross keying necessary
• Special application cylinders (Brinks function, Lockout cylinders, elevator cylinders)

The recommendations for selecting a master key combination:


1. Have at least one of the deepest possible depths of cut
2. Have at least one of the shallowest possible depths of cut
3. Not be a declining step key
4. Not be a straight line key
5. Not have the deepest cut at the bow of the key
6. Not have the shallowest cut at the tip of the key
7. Observe all other rules for the cylinders it will operate
   
   *Above list taken from "Master Keying by the numbers" by: Billy B. Edwards Jr., CML

So you are stuck with the progression of change keys for a master key system...

There are two major methods of progressing change keys in a master system:


• Total Position Progression (TPP) a.k.a. "odometer method"
• Rotating Constant (RC) a.k.a. "hold and vary"

Then within those methods depending on what type of locks and the bitting system you are using with them you can have:


• single-step progression
• two-step progression

I keep mentioning "bitting system" because it is important, with locks like Corbin-Russwin you are always looking at determining whether your keying system is System 70 (.028" increments) which is single-step vs. Pre-System 70 (.014" increments) which is two-step... It is also a factor with SFICs whether you are dealing with two-step A2 (.0125" increments) vs. A3 (.018" increments) or A4 (.021" increments) which are single-step...

If you would like a deeper explanation reply to this thread with any questions you have and I can post an example of what you would like explained with more detail...

~~ Evan

[SoMotivated10]

Thank you for your time and response. I appreciate it. . I will take what you have said in to consideration as it does help some.

My main concern is amongst other things. . I do not even know where to start with my questions. lol

ok here goes. .

Say you have a GMK with the bitting cuts as follows: 47230

KBA=
GMK=47230

69452
81674
03896
25018

Those 4 listed above would be my MKs.

For these, how do I come up with the CK combinations? How do I figure out the Master Pin and the Bottom Pin combinations as well?

I guess we can start here in hopes that I can finally understand this whole theory and how to get results if I was to create a simple Master Key System. I would like to understand so that I can further practice and feel comfortable knowing exactly what is going on.

Thank you again and I appreciate you taking the time to help me.

[keysman]

Say you have a GMK with the bitting cuts as follows: 47230

KBA=
GMK=47230

69452
81674
03896
25018

Those 4 listed above would be my MKs.

Why those? Why not choose subs that work with your GM?

For these, how do I come up with the CK combinations? How do I figure out the Master Pin and the Bottom Pin combinations as well?

There are different methods of writing a master keys systems but a common one is called a progression: see the example below for an Idea of what it entails.




KBA=
GMK=47230


A xxxxx B xxxxxx C xxxcc Dxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
/\ xxxxx /\ xxxxxx /\ xxxx /\ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Sub Master 47430 xxx 47630 xxx 47830xxx 47030 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

47432xxx 47632xxx 47832xxx 47032xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
47434xxx 47634xxx 47834xxx 47034xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
47436xxx 47636xxx 47836xxx 47036xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
47438xxx 47638xxx 47838xxx 47038xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
47450xxx 47650xxx 47850xxx 47050xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
47452xxx 47652xxx 47852xxx 47052xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
47454xxx ect.xxxx ect.xxxx ect.xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

The lower group is the change keys under each submaster

To figure out how to pin it up

Master 47230
Change 47452
-------------
xxxxxxxxxxxxxxxxxcccccc --222 Top pins (Master)
xxxxxxxxxxxxxxxxx 47230 Bottom Pins

So when subtacting to find bottom pins use the Absolute Value (ie 5-7 = 2 absolute value)

Sorry I can't get the columns to line up properly.
hope this helps ask if you have any questions

[Evan]

Thank you for your time and response. I appreciate it. . I will take what you have said in to consideration as it does help some.

My main concern is amongst other things. . I do not even know where to start with my questions.

Your questions are important... The only way to learn this sort of stuff is to ask people who have knowledge of it to explain to you the parts you are having difficulty understanding...

I should have mentioned in my previous post in this thread that the "recommendations (or rules) of selecting a master key combination" only apply to the selection of the Top Master Key (TMK) for your keying system...

Say you have a GMK with the bitting cuts as follows: 47230

KBA=
GMK=47230

69452
81674
03896
25018

Those 4 listed above would be my MKs.

Did you select these combinations yourself for a new theoretical keying system or are they bittings from a real system that already exists?

Hopefully these are just theoretical, as in order to make any change keys work with this system with the TMK and MK's you have listed would require double-pinning in just about every chamber of every lock and you would experience terrible unintended key interchange...

The system you have described seems to be a Three-Level master keying system...

Three Level System --
level of keying / (key name) / abbreviation: / key symbol


• level III (Grand Master) GMK: A
• level II (Master Key) MK: AA, AB
• level I (Change Key) CK: AA-1, AA-2
  
  *Above chart is from the description of the Standard Key Coding System (SKCS)

These systems are usually very small with standard 5-pin locks and would require advanced techniques including using multiple compatible keyways in order to have larger numbers of change keys under each master key group...

Since this is not a simple Two Level system, you must "divide" the key into pieces to progress the various levels of keying for your system... Different options will reduce the total number of keys possible in your system... From the information you have provided so far it is a two-step progression system so that means we will be dealing in multiples of 4.

If your system was a simple Two Level system it would have the following capacity:

4 x 4 x 4 x 4 x 4 = 1,024 (or 4 ^ 5) (Without factoring in MACS losses!)

Since your system is more complicated some of those potential keys will not be available depending upon how many master key groups you require...

Let's look at the example provided by Keysman in his response...

KBA=
GMK=47230


A xxxxx B xxxxxx C xxxcc Dxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
/\ xxxxx /\ xxxxxx /\ xxxx /\ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Sub Master
47430xxx 47630xxx 47830xxx 47030 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

47432xxx 47632xxx 47832xxx 47032xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
47434xxx 47634xxx 47834xxx 47034xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
47436xxx 47636xxx 47836xxx 47036xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
47438xxx 47638xxx 47838xxx 47038xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
47450xxx 47650xxx 47850xxx 47050xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
47452xxx 47652xxx 47852xxx 47052xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
47454xxx ect.xxxx ect.xxxx ect.xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

So we have:

GMK 'A': 47230
MK 'AA': 47430
MK 'AB': 47630
MK 'AC': 47830
MK 'AD': 47030

For these, how do I come up with the CK combinations?

As you see he has progressed the 3rd chamber to develop the master keys... Each of the 4 master keys currently has a total of 16 potential change keys under it...

Key Bitting Array:
4 7 2 3 0
6 9 4 5 2
8 1 6 7 4
0 3 8 9 6
2 5 0 1 8

Keysman has made an error in his progression of the change keys however the proper way is listed below...

Code: Select all

Sample Three Level Master Keying System using the Total Position Progression method and two-step progression between different bittings...

GMK A 47230

MK AA 47430                  MK AB 47630                  MK AC 47830                  MK AD 47430

AA-1  47452  AA-9   47492    AB-1  47652  AB-9   47692    AC-1  47852  AC-9   47892    AD-1  47052  AD-9   47092
AA-2  47454  AA-10  47494    AB-2  47654  AB-10  47694    AC-2  47854  AC-10  47894    AD-2  47054  AD-10  47094
AA-3  47456  AA-11  47496    AB-3  47656  AB-11  47696    AC-3  47856  AC-11  47896    AD-3  47056  AD-11  47096
AA-4  47458  AA-12  47498    AB-4  47658  AB-12  47698    AC-4  47858  AC-12  47898    AD-4  47058  AD-12  47098
AA-5  47472  AA-13  47412    AB-5  47672  AB-13  47612    AC-5  47872  AC-13  47812    AD-5  47072  AD-13  47012
AA-6  47474  AA-14  47414    AB-6  47674  AB-14  47614    AC-6  47874  AC-14  47814    AD-6  47074  AD-14  47014
AA-7  47476  AA-15  47416    AB-7  47676  AB-15  47616    AC-7  47876  AC-15  47816    AD-7  47076  AD-15  47016
AA-8  47478  AA-16  47418    AB-8  47678  AB-16  47618    AC-8  47878  AC-16  47818    AD-8  47078  AD-16  47018

You would have to decide right at the beginning of the system whether or not you wanted to be able to expand it at all in the future... The way things are keyed right now the system is at its maximum expansion because ALL change keys share the first two cuts in common with the system TMK... You will not be able to progress the first two columns at all to create any new change keys because the existing keys share the master key level cuts... If you would want to expand the system in the future without doing a complete re-key job all the change keys would have to start with 69xxx instead of 47xxx... That way you would be able to progress the first two columns into new change keys without creating any key interchange (the existing change keys would all act as IMK "depth" master keys allowing access to any of the 16 additional keys you would progress from the first two columns of the KBA)...

Depending on what your lock manufacturers MACS specifications are several of the change key combinations under MK AD would be unusable...

How do I figure out the Master Pin and the Bottom Pin combinations as well?

Keysman gave a good example of that... But let me explain it in words and show another example:

For each unique keying specification in the system you would take the keys which should operate the cylinder and write them down in a list... For each chamber you would take the smallest cut and use that as your bottom pin... You then add master pins to make up the difference between the shallowest cut in each position and the additional deeper cuts which must also operate by adding one or more master pins in that chamber as as required to make all intended keys operate... Care must be taken when you are adding more than one master pin per chamber -- key interchange will result unless such pinning was planned for and the cross keying accommodated by reserving and not using the change keys which you do not desire to operate such cylinders...

A thread here from last year discusses cross keying in more depth... Here is that thread: Master Key Systems (OP: Shangri-laschild)

I guess we can start here in hopes that I can finally understand this whole theory and how to get results if I was to create a simple Master Key System. I would like to understand so that I can further practice and feel comfortable knowing exactly what is going on.

Thank you again and I appreciate you taking the time to help me.

Well Keysman and I have explained and shown the Total Position Progression (TPP) method of creating a master key system... There are a couple of more ways to create master keying systems, I am also familiar with Rotating Constant (RC) as well and could explain that to you if you wanted... Please feel free to ask any more questions or for clarifications of anything which has been posted thus far in this thread as you need...

~~ Evan

[globallockytoo]

I agree with both Evan and keysmans sentiments.

Their answers are very well explained.

However, I personally believe that instead of a 2 depth difference, you should consider a 3 depth difference, depending on the manufacturer of choice. If using Schlage or Kwikset, then a depth change of 3 would be advised because of the poor tolerances in their cylinders.

Of course considering MACS, this will rule out a significant number of key changes.

2 depths is the norm but is also easier to find phantom keys (that dont appear in the system charts - but accidentally work in worn cylinders or miscut keys)

[Evan]

I agree with both Evan and keysmans sentiments.

Their answers are very well explained.

However, I personally believe that instead of a 2 depth difference, you should consider a 3 depth difference, depending on the manufacturer of choice. If using Schlage or Kwikset, then a depth change of 3 would be advised because of the poor tolerances in their cylinders.

Of course considering MACS, this will rule out a significant number of key changes.

2 depths is the norm but is also easier to find phantom keys (that dont appear in the system charts - but accidentally work in worn cylinders or miscut keys)

globallockytoo gives some good advice as far as increasing the steps-difference with worn cylinders, however if the cylinders were _that_ worn so you would have to resort to adding an additional increment to a Kwikset or Schlage cylinder you should definitely consider replacing them if you want your master keyed locks to function properly... You should replace residential grade locks that worn and if you are talking about real solid brass lock cylinders they are either decades old or experience thousands of daily uses and need replacement rather than keying system design accommodation...

Let's assume 5-pin locks and TPP method of progressing change keys --

Schlage which uses 10 depths of (.015"), 0-shallow through 9-deepest...
Standard two-step progression: Evens, 0, 2, 4, 6, 8 or Odds, 1, 3, 5, 7, 9 after removing one combination for TMK bitting =

4 x 4 x 4 x 4 x 4 = 1,024 possible different theoretical change key bittings (4 ^ 5)

Now change that to three-step progression: You would end up with 0, 3, 6, 9 or 1, 4, 7 as your bitting options in a given chamber, now remove one combination for TMK bitting =

3 x 2 x 3 x 2 x 3 = 108 possible different theoretical change key bittings

If your pot-metal F-series cylinder plugs for a Schlage residential lock are that worn to necessitate reducing the potential size of the keying system capacity by ~90% to accommodate the wear (remember MACS, a 0 or 1 can not be next to a 9 so you will lose several more possible change keys), upgrade to a real lock with a brass cylinder plug or purchase brand new res-grade locksets if you are creating a new master key system for locks worn in such a manner...

Kwikset which uses 6 depths of (.023"), 1-shallowest through 6-deepest (7 on construction master keys)...
Standard one-step progression, after removing one combination for TMK bitting =

5 x 5 x 5 x 5 x 5 = 3,125 possible different theoretical change key bittings (5 ^ 5)

Now change that to a two-step progression: You would end up with 1, 3, 5 or 2, 4, 6 as your bitting options in a given chamber, now remove one combination for TMK bitting =

2 x 2 x 2 x 2 x 2 = 32 possible different theoretical change key bittings (2 ^ 5)

That greatly reduces the potential size of the systems possible following the standard master keying practices allowable under the manufacturer's guidelines...

I agree that Kwikset cylinders do wear ungracefully and that a prudently designed master key system for Kwiksets would avoid using #1 master pins and have its keys be at least 2 increments deeper or shallower than the master key bitting, so with a #1 cut on the master key you would use #3, 4, 5 and 6 for change keys... Or with a #4 on the master key, you would use #1, 2 and 6 on the change keys...

You would have to employ the Rotating Constant method of master keying on those increased step increment keying systems and would only get slightly better potential theoretical change key yields...

~~ Evan

[SoMotivated10]

You guys are awesome. . Although I have not thoroughly read the posts as of yet I can see the time you have put in to helping me and I appreciate it so much.

I will be printing the replies from work tomorrow so that I can read it through as the computer hurts my eyes at times.

I have not had too much time today as I have had some things to take care of after work, but I look forward to gaining a further understanding. .

I will reply to you guys and let you know my feedback. . Hopefully I understand it better and can really have a grasp on it.

Thank you guys so much. This was a lot more then I had expected and I am very pleased in your responses.

[SoMotivated10]

Ok, so I have reviewed everything that was said and I just want to give my response in a simple form to explain in my own words how I understood the basics of what was taught to me by you guys. .

Would just like to say that the system and numbers I used were straight from my text book and after reviewing your responses it seems that the example the book used was a pretty poor one to introduce Master keying systems. I think most people would feel lost.

So Here's my feedback:

TMK : 47230

Any master key made from that would basically be changed from the 3rd chamber as you guys described.

So my Master keys would be

47430
47630
47830

ect.

Then If I wanted to keep it at a two step progression without complications later, my best bet would be to creat change keys using 69xxx rather then 47xxx.

So for this my change keys would be for example using the 2 step progression. .

69652
69874
69096

ect. correct?

hopefully I am understanding this more. .

Questions:

When describing the 2 level system how come you use 4 x 4 x 4 x 4 x 4= (4 ^ 5) How come you use 4? Whats does this formula represent?

does that represent chamber 4 and that's how many combinations you can create from changing the 4th chamber? A little confused, I apologize.

Also was just wondering if you can show me a simple Master key system chart for Levels 2 through 5 Just so I can see how it looks.

As you stated the example I gave was a complicated one so I am curious as to how others would look.

Again, thank you and I appreciate your time in showing me to help me learn.

[Evan]

Ok, so I have reviewed everything that was said and I just want to give my response in a simple form to explain in my own words how I understood the basics of what was taught to me by you guys. .

Would just like to say that the system and numbers I used were straight from my text book and after reviewing your responses it seems that the example the book used was a pretty poor one to introduce Master keying systems. I think most people would feel lost.

So Here's my feedback:

TMK : 47230

Any master key made from that would basically be changed from the 3rd chamber as you guys described.

So my Master keys would be

47430
47630
47830

Yes... You could progress a total of four level II master keys using the 3rd chamber...
If you needed more you could progress one additional chamber and have a total of 16 level II master keys...

Then If I wanted to keep it at a two step progression without complications later, my best bet would be to creat change keys using 69xxx rather then 47xxx.

So for this my change keys would be for example using the 2 step progression. .

69652
69874
69096

Yes... Each of the change keys you listed above would exist under a different level II master key...

Questions:

When describing the 2 level system how come you use 4 x 4 x 4 x 4 x 4= (4 ^ 5) How come you use 4? Whats does this formula represent?

This is two-step progression system size math... Given a Schlage system you would need to use bitting parity (odds or evens, and there is a whole method of progressing that so you can create multiple systems on the same keyway in a given geographical area without knowingly creating the possibility of key interchange with different customer's systems) so with the bittings: Even - 0, 2, 4, 6, 8 & Odd - 1, 3, 5, 7, 9 in a TPP system you remove one possible bitting depth for your TMK combination leaving you 4 depths per chamber remaining to progress your keying system...

So your theoretical possible change keys before MACS losses goes like this:

4 x 4 x 4 x 4 x 4 = 1,024 keys (5-pin locks) (4 ^ 5)

4 x 4 x 4 x 4 x 4 x 4 = 4,096 keys (6-pin locks) (4 ^ 6)

4 x 4 x 4 x 4 x 4 x 4 x 4 = 16,384 keys (7-pin locks) (4 ^ 7)

Those numbers are effected by the available bittings available to progress... In a system with 6 depths and single-step progression you would be multiplying by 5 instead of 4...

does that represent chamber 4 and that's how many combinations you can create from changing the 4th chamber? A little confused, I apologize.

No, it is the mathematics of master keying... 4 is the multiplier per chamber progressed for keying with a Schlage two-step progression keying system...

Also was just wondering if you can show me a simple Master key system chart for Levels 2 through 5 Just so I can see how it looks.

Sure, I will make a separate post for that here to make it more clear to understand...

As you stated the example I gave was a complicated one so I am curious as to how others would look.

Again, thank you and I appreciate your time in showing me to help me learn.

A level three system is middle of the road -- unless you start adding selective master keys like ENG, JAN, ATT, GRD, NUR, etc which can be keyed in and out of any lock in the system...

I will post the examples of the various levels soon, that last bit of "code" in my reply yesterday took a while to figure out how to type it into the forum properly...

~~ Evan

[Evan]

Code: Select all

Standard Key Coding System (SKCS) specifications on "levels of keying" which are as follows:

level of keying / (key name) / abbreviation: / key symbol

Two Level System --

level II  (Master Key)     MK:  AA
level I   (Change Key)     CK:  1AA, 2AA

Three Level System --

level III (Grand Master)  GMK:  A
level II  (Master Key)     MK:  AA, AB
level I   (Change Key)     CK:  AA-1, AA-2

Four Level System --

level IV   (Great Grand Master)  GGMK:  GGMK
level III  (Grand Master)         GMK:  A, B
level II   (Master Key)            MK:  AA, AB
level I    (Change Key)            CK:  AA-1, AA-2

Five Level System --

level V    (Great Great Grand)   GGGMK:  GGGMK
level IV   (Great Grand Master)   GGMK:  A, B
level III  (Grand Master)          GMK:  AA, AB
level II   (Master Key)             MK:  AAA, AAB
level I    (Change Key)             CK:  AAA-1, AAA-2

Six Level System --

level VI   (Great Great Grand)   GGGMK:  GGGMK
level V    (Great Grand Master)   GGMK:  A, B
level IV   (Grand Master)          GMK:  AA, AB
level III  (Master Key)             MK:  AAA, AAB
level II   (Sub-Master)            SMK:  AAAA, AAAB
level I    (Change Key)             CK:  AAAA-1, AAAA-2

[SoMotivated10]

Thanks Evan. . I won't sweat how an actual master key system will look for all those levels right now as I am sure my experience in the real world will teach me.

So upon my previous reply do you feel that I understood correctly and have a grasp on the basic concept behind Master key systems?

I feel I have a better understanding of it now.

I appreciate all your help.

[acedrew]

OK, so I guess I have a lot of work to do on my Master key Generator, right now, it would produce a a lot of key intersections...

I'll have to do some more research...

If someone wants to take a look at what it does so far:
SOOO I built a schema generator. It's a little ugly, but it works, right now it will generate (from a master you specify) (n) group masters with (n) sub keys for each group. It will generate most key types, although some of the parameters are hard coded at this time.

Right now it is hosted as a Google App Engine app, you can access it here:
http://pymasterkey.appspot.com
By default it generates 10 groups with 10 group masters, for a total of 110 keys based on a master key code of 555555, it also generates codes 0-9, as most of my locks are SC4, that is what I mess with most of the time.
Here is another example:
"http://pymasterkey.appspot.com?code=053525&groups=7&keys=5&type=6"

This would generate 7 groups of 5 keys each, with a type of 6, meaning that each pin can be a value of 0-5 with a master key of 053525
One of the parameters that is not currently editable, but is included in the application, it maximum adjacent cut difference, it is hard coded at 5. This means that a 0 next to a 5 is ok, but a 0 next to a 6 is not. Also, it is set to generate no more than 2 identical adjacent pins, meaning that 567740 is a valid code, but 577740 is not.

[Evan]

OK, so I guess I have a lot of work to do on my Master key Generator, right now, it would produce a a lot of key intersections...

I'll have to do some more research...

If someone wants to take a look at what it does so far:
SOOO I built a schema generator. It's a little ugly, but it works, right now it will generate (from a master you specify) (n) group masters with (n) sub keys for each group. It will generate most key types, although some of the parameters are hard coded at this time.

Right now it is hosted as a Google App Engine app, you can access it here:
http://pymasterkey.appspot.com
By default it generates 10 groups with 10 group masters, for a total of 110 keys based on a master key code of 555555, it also generates codes 0-9, as most of my locks are SC4, that is what I mess with most of the time.
Here is another example:
"http://pymasterkey.appspot.com?code=053525&groups=7&keys=5&type=6"

This would generate 7 groups of 5 keys each, with a type of 6, meaning that each pin can be a value of 0-5 with a master key of 053525
One of the parameters that is not currently editable, but is included in the application, it maximum adjacent cut difference, it is hard coded at 5. This means that a 0 next to a 5 is ok, but a 0 next to a 6 is not. Also, it is set to generate no more than 2 identical adjacent pins, meaning that 567740 is a valid code, but 577740 is not.

You need to learn a lot more about master keying before you offer this app for sale...

Hard-coded variables = bad...

Using a master key bitting of: 555555 = bad...

You need to read and review the above master key bitting selection guidelines and figure out how to program them in as variables to select a bitting code for a system top master key... Then it can generate a system off of that... You would need to program in a parameter table for each bitting system under each manufacturer...

It would also be beneficial if your app could use the SKCS method of organizing master key systems...

~~ Evan

[SALocksmith]

It's definately good to know how to do the math on paper. But most lockshops just use software that generates huge systems automagically. Like HPC Master King. My boss could write a huge system by hand, but im a bit ashamed to admit, that i could not do it. I don't think i'll ever need to though. I think I know a bit more about keying up IC Cores, which are actually much more complicated then I know about keying up standard cylenders. But only because I was forced to learn, boss calls up with a weird request, he needs IC Cores Cross Keyed (somthing we typically would avoid) or needs the TMK to be "broken" but the control key to still work and change key. etc, weird situations like that will force you to figure it out when you need to.