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Sep 22 2016

Intro to Keying Terms (video)

Category: Locks & Keys,VideosLori @ 12:08 am Comments (14)

Last night, my oldest daughter told me that her science assignment was to explain how inclined planes are used in keys.  She had researched it, and described how the pins go into the cuts on the key, and of course I had to supplement her education with TMI about shear lines, master pins, bitting lists, etc.

I love master keying!  I’m sure I drove our locksmith crazy (Hi Louise!), asking if I could help in the shop.  One day one of my coworkers (Hey Don!) taught me how to shim a cylinder, and I was a natural!  I shimmed my first cylinder while answering a code question on the phone.  🙂


I admit (despite my immediate love of keying)…keying terminology can be confusing.  So we made a whiteboard animation video to help explain some of the common terms.  Enjoy!

The rest of our whiteboard animation videos can be found on the Allegion Training page, or on the Videos page of

What other topics would you like to see addressed in future videos?

Key animation by Stian Berg Larsen.

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14 Responses to “Intro to Keying Terms (video)”

  1. Tony says:

    Like mother, like daughter! 😉

  2. metis says:

    Background: I work in architecture, frequently specifying hardware, and for fun have been hobby lockpicking/studying physical security for about 20 years. Locksport organizations such as TOOOL and LSI offer a lot of great resources for understanding how locks work, and Allegion does a lot of really great education, but there’s misinformation in this video. (note, locksport as a community is quite serious about ethical security research and ethical use of knowledge to increase security and security awareness, despite a decent amount of push back from trading locksmiths and lock manufacturers mostly where they pushing security through obscurity)

    In most commercial applications, interchangeable cores are used, which dramatically increases picking difficulty, as the addition of a secondary shear line at the control sleeve requires specialized tension tools to pick, if the control sleeve doesn’t have up to date security features. If newer control sleeve design is used, they become much harder to pick.

    A traditional core is easier to pick when master keyed, but that installation is much rarer.

    • Lori says:

      Thanks for sharing your insight. Can you tell me what specifically you consider misinformation, so I can clarify?

      – Lori

      • metis says:

        Sure, the dialogue starting around 2:05~3:00 has a few problems.

        Master keying in a IC system is more difficult to pick as there are 2 possible shear lines, and all pins must be picked to the same shearline to open or remove the lock. Control of one shear line is possible, but requires non-“standard” lockpicking equipment, and not an up to date lock design. If the control sleeve is up to date, it becomes much harder to pick than a non master keyed system.

        Master keyed system are vulnerable to rights escalation attacks by authorized users, but that’s not picking- it’s an internal security threat requiring an operational key, and an exploit that’s functionally moot. There are other key duplication exploits available that don’t require prior access to a lock or even close physical access to the key. Simply having more authorized users for any lock is a much bigger threat in high security applications.
        Realistically any attacker sophisticated enough to learn to pick well enough to compromise a 6/7 pin core in a useful amount of time is going to use an easier exploit.

        Only in a non interchangeable core system does a master keyed system become easier to pick, as you have 2 opportunities to pick each pin, but I can’t think of the last time I saw a non IC master keyed system in “the wild”.

        Unless Schlage MACS has changed, a 6 pin has about 750K combinations not 1 million. If the lock is pinned per mfg recommendations. That’s not desirable keys, just total possible combinations. It includes keys that pinned with the same depth throughout, and other undesirable pinnings. With what I understand to be good practice it’s only about 125K “good” key bitings on a 6 pin, 9 depth, MACS7 lock. (not my combinatorics, but as I understand them, correct)

        • Lori says:

          Thanks for adding this info. The video is part of our “Intro to Hardware” series, and is meant to be an introduction to keying terminology. At some point in the future we may do a more in-depth video on the technical aspects of keying as there is much more than could be covered in a short video. I’ve passed your comments on to our training department to take a look and see if we need to make a change to the introductory video. We appreciate the feedback!

          – Lori

  3. metis says:

    I take that back, I do recall a non IC master keyed system. It was a lever lock system in an old bed and breakfast in Scotland, which is a whole different barrel of worms, although vulnerable to similar (in theory different in practice) methods of rights escalation/migration. Handsome big old keys.

  4. Louise says:

    I’ve started to plan for retirement and have suggested to my boss that they contact you to see if you want to be my replacement. Mr. Carrier is here too.
    Bone up on SFIC. I have several thousand doors.

    • Lori says:

      Hmmmm…as much as I do love keying, and Vermont, I think my family would revolt if I made them move again. 🙂

      Say hi to Mark!

      – Lori

  5. Chuck Park says:

    Background: I have designed Masterkey systems for over thirty years. Not as a hobbyist, but as my life’s work.
    I have to disagree with you on a few points.
    I see no misinformation in the video. It merely speaks in broad, non specific terms to describe a generic-type master system. In this type of conversation (that is aimed at customers that may not be keying-savvy), bringing topics such as MACS; Rotating Constant; IC/non-IC; shearlines; Odometer method; etc would only serve to confuse the viewer and draw their attention away from the point of the video.
    An IC’s control shearline does not necessarily make that cylinder more difficult to pick to the operating shearline. The only cylinders with two shearlines that definitely inhibited picking were the old Corbin Masterring cylinders because both shearlines were separate operating shearlines.
    There are plenty of non-IC master systems out there. They are mostly older systems, because years ago there were not many manufacturers offering ICs. In my area, many schools, hospitals, and public buildings are very old. Some remain non-IC only because it can be too expensive to change hardware over to IC from conventional cylinders.

  6. JBange says:

    Metis- I work for a school district with over 1000 separate facilities, all of them master keyed, none of them interchangeable core, primarily because we use semi-restricted 7-pin Sargent and Corbin/Russwin cylinders, which are not available as LFIC. I know of at least three other unrelated large facilities that do the same. Master keyed systems using non-IC cylinders are not anywhere near as rare as you imagine.

  7. Robert says:

    Hi everyone
    Its interesting to see how the facts get so picked apart HAHA for some of the difference in the types of lock cores. Yes ok with a few types of locks I/C or Mastered locks to be set on the top of the list to e sure to see the facts if its easier to pick or not? I have picked HS locks too but if the know of how it is to be sure of how to pick is a fact as its a great fun life
    I have been in both field to pick I/C locks and if there are more than 1 shire line than yes its easer to pick open. I am not trying to be the one to say this but I have been on both sides of the fence to be sure. Both being the one to pick open and the one to be on the teaching side to show that this is a fact on the higher side of the security side of life. yes there is a fact that the Best is a good lock for sure BUT it is a fact that if there are 2 shear lines that than the fact is that there are 2 times to open. I have worked on both sets and do like BEST but the fact is if there are 2 shear than the fact is that its easy to open but you got to be able to PICK yes PICK IC locks are not for the beginner but it is a fact. Yes ok I have been in industry for more than FEW WEEKS TOO AND OK I have been the chairman for the security industry for more than a few years its a fact that I am saying that if there is a way than it can be picked by some people here
    have a great week and truth be sure the real facts but most enjoy the art of trying to pick as I still do try hard to be just right tension artist

  8. David Webb says:

    I agree with JBange non-IC master keyed systems are not rare in institutional facilities.
    Any one using a full size Schlage removable core system is using a non-IC system.
    Lori would be able to get a better handle on how much of that system is in the field.

  9. David Barbaree says:

    This video is very good. Overall it is an excellent “Intro to Keying Terms.”

    I might have liked to see various terms detailed a little more, maybe with a drawing showing a key level hierarchy with a bit more explanation, but I’m not sure if that would add to the simple understanding this video currently provides.

    Experts in any particular field can get lost in the details when a manufacturer makes statements regarding their products. Every statement does not require a challenge for 100% accuracy. The purpose of the statement should be considered. In regard to this video, the simple purpose and simple message is as accurate as it needs to be to inform the general (non-expert) public.

  10. DAVID FEDERICO says:

    Having been in the locksmith and security industry for over thirty plus years I must say there still exists today the debate of picking . Picking in simple terms is just the act of opening a lock without it’s operating key. This can be done with conventional picking tools or even with key manipulation. However this video is just to inform and give insight into some terms they may hear in and around buildings and security personnel . I think keeping it simple and putting it in layman’s terms was best

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