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Interchangeable core general knowledge....

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mdc5150

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Post Tue Mar 04, 2014 6:59 am

Interchangeable core general knowledge....

I put this together as a reference for everyone to get an understanding of what interchangeable cores are, and the differences in the different types. Interchangeable cores have been around for a very long time, Frank Best first patented the IC core idea in 1923. I don't know much more about what the petent looked like etc but I wanted you to get the idea it has been around for a long time.

In general interchangeable or removable cores are a great tool for a locksmith. One of my favorite applications for IC is on panic hardware and pilfer guards. (Pilfer guards are the devices that make lots of noise when someone leaves out a door they should not have) Sometimes taking apart panic hardware is a real pain depending on the type, and the quality of the installation and who has been rekeying it. Other applications where I/C cores are frequently used are in padlocks, file cabinet/medical cart locks, cam locks, desk locks, drawer locks, key switches, and you can even see them on FedEx and UPS trucks as well as armored cars. While doing a little bit of research for this article I read that there are over 2 billion cores in use all over the world.

As for the different types of cores there are I have to start with the Small Format Interchangeable Core A/2 system. There are 3 SFIC systems A/2, A/3, and A/4. From what I understand A/3 is not used very much and A/4 is typically used in institutional locksmithting.
A/2 is hands down the most widely used system of the three, and although they all share the same hardware and keyblanks, (they also use the same keyblanks no matter if it is a 5, 6, or 7 pin core since they are all cut tip to bow) the pin kits make the difference. A/2 pinning uses a system where each pin stack must equal 23. So if you have a 3 and a 2 for your change key and master key pins, and a 10 for your control pin, your makeup pin must be an 8. I won't dive too much into the pinning here, I just want you to get the idea I'm not trying to teach how to pin them up.
So for SFIC you have your change or user keys depending on your choice of terminology, and a control or core key to remove and place the cores. The control key does not use a special blank, it is a normal blank and it is cut to the control bittings. SFIC cores can be masterkeyed the same way you would masterkey any other lock as long as you are using a 2 step progression system since there is no #1 top pin. You can also masterkey the control bittings. This is something I have done pretty frequently where the IC core its self is the lock in a new type of sliding door lock system. When the control key is used it draws the control lug into the housing of the core so that the core can be removed.
Below is a picture of an SFIC taken apart so that you can see the plug, control sleeve and housing separately.

IMG_20140303_105915.jpg




The photo shows a Schlage Everest SFIC core that I use for one of our customers. You can see the check pin in the locked position and then again with the key inserted it is retracted.

Schlage SFIC rest.jpg


Schlage SFIC with key.jpg






This is a photo of my A/2 pin kit. Though this kit did not originally come equipped with nickel-silver pins that is what I stock it with now. Nickel-silver pins last much longer than brass pins.

IMG_20140303_104501.jpg




This is the chart that shows the pin number and the pin length in thousandths of an inch.

IMG_20140303_104509.jpg




These are my pinning tools, a Lab Annex which allows me to not only cap cores, but also dump a core into a "book" that allows me to decode the core so that I can find a core key bitting or a master key bitting. The four pronged tool dumps 4 chambers at a time, there is another for dumping only one and finally the capping tool.

IMG_20140303_104619.jpg


This is the "book" from the Annex with a core dumped into it.

IMG_20140303_104949.jpg


At the back of the A/2 core are two holes on either side of the keyway. Those holes are where the tailpieces interact with the core and open locks when the key is turned.

IMG_20140303_105736.jpg




As for who makes A/2 cores? Well just like everything else in the lock world there are a bunch out there who make A/2, as you've already seen, Schlage makes A/2, there is Best of course, Falcon, Medeco Keymark, KSP, Arrow, CX5 and many others that I can not think of right now. Although they all share the A/2 system, and they all are made up going tip to bow, the only differences there really are is that some are shoulder stopped rather than tip stopped.

So, now to move on to LFIC or LFRC, (large format interchangeable cores, or large format removable cores). Among the manufacturers of these are Schlage, Mul-T-Lock, Sargent, Medeco, Yale, Corbin-Russwin and probably a few others. Mul-T-Lock uses the Schlage format which makes it easy to get hardware to support it. As for the others I don't honestly know if any of them share a format. Schlage, Mul-T-Lock and Yale use a special key to act as a control key, but Sargent, ASSA (I think) and Medeco use normal keys cut to a particular bitting to pull the control lug back.

Below are two unlabeled Sargent cores, one picked to control.

Sargent.jpg


A Corbin-Russwin core that I can only pick to operate.

IMG_20140303_221600.jpg


A Schlage LFIC core

IMG_20140303_113718.jpg


A Schlage LFIC control key, you can see that at the tip is a flat cut to a #6 depth, this lifts a pin at the rear of the housing and when the key is turned it pulls the control lug in.

IMG_20140303_221625.jpg


And a Mul-T-Lock core and key. The key can only be inserted one way and works the same as a Schlage.

IMG_20140303_221514.jpg



I hope this has been helpful. This was by no means meant to be a complete course, just to introduce you to the basics.
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GWiens2001

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Post Tue Mar 04, 2014 12:44 pm

Re: Interchangeable core general knowledge....

MDC - Thank you for this informative post. Am sure that a lot of people will find it useful.

Had heard that the Everest and Everest Primus have the check pin at the front on their SFICs, but had not seen it in person. Have been wanting an MTL LFIC for a while, but there are hard to come by. Did not know they took a special blank for the control lug. Cool stuff.

Gordon
Just when you think you've learned it all, that is when you find you haven't learned anything yet.
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ARF-GEF

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Post Tue Mar 04, 2014 1:11 pm

Re: Interchangeable core general knowledge....

What a great and very useful post!
IC core are absolutley unkwon here so it took me a long time to understand them. This post really helped me clear a lot of questions and got my patch knowledge a lot more orderly :)
Thank you very much for writing it! :)
To infinity... and beyond!
=== WARNING DANGER OF TYPOS!===
Arfspeak: calnin cladycomes: you allow her key in themodning
Equals in plain English: cleaning lady comes: you allow her key in the morning
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jeffmoss26

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Post Tue Mar 04, 2014 1:16 pm

Re: Interchangeable core general knowledge....

Excellent post!!
macgng: i just thought the cat was a real tiny bear
GWiens2001: Great video! Learned a lot about what fun can be had with a forklift and a chainsaw.
pmaxey83: but i first have to submit the proper forms for a new hobby to my wife
xeo: i root for the kernel
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Alaphablue

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The only difference between me and this crazy island is that I'm a madman!

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Post Tue Mar 04, 2014 2:04 pm

Re: Interchangeable core general knowledge....

Very nice post Sfic are one of my favorite lock types. best locks sfic were truly ahead of there time and still being used with barely any alteration from the original design .
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mastersmith

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Post Tue Mar 04, 2014 5:50 pm

Re: Interchangeable core general knowledge....

Terrific post. Its difficult to believe someone hasn't done this before now. Keep this one going.
"All ye who come this art to see / to handle anything must cautious be...." Benjamin Franklin
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jeffmoss26

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Post Tue Mar 04, 2014 6:21 pm

Re: Interchangeable core general knowledge....

WHERE IS RIY??
macgng: i just thought the cat was a real tiny bear
GWiens2001: Great video! Learned a lot about what fun can be had with a forklift and a chainsaw.
pmaxey83: but i first have to submit the proper forms for a new hobby to my wife
xeo: i root for the kernel
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xeo

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Post Tue Mar 04, 2014 9:55 pm

Re: Interchangeable core general knowledge....

Something is sticky in here.
Image
The code is hidden in the tumblers. One position opens the lock, another position opens one of these doors...
http://www.youtube.com/xeotech1

(ノಠ益ಠ)ノ彡┻━┻

░░░░░░░░░░░░░Image
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ARF-GEF

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Post Tue Mar 04, 2014 10:00 pm

Re: Interchangeable core general knowledge....

Ewww spare us from the details of what's stiky :S :S :S

Lol well deserved mdc5150! :)
To infinity... and beyond!
=== WARNING DANGER OF TYPOS!===
Arfspeak: calnin cladycomes: you allow her key in themodning
Equals in plain English: cleaning lady comes: you allow her key in the morning
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Oldfast

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OldddffAASSTT the Spin Master Extraordinaire and American Lock Slayer
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Post Sun Mar 09, 2014 3:29 am

Re: Interchangeable core general knowledge....

INDEED! A very well deserved sticky! Thanks so much for putting this together.

A very nice general overview, without the overkill (which confuses someone like me) lol.

mdc5150 wrote: A/2 pinning uses a system where each pin stack must equal 23. So if you have a 3 and a 2 for your change key and master key pins, and a 10 for your control pin, your makeup pin must be an 8. I won't dive too much into the pinning here, I just want you to get the idea I'm not trying to teach how to pin them up.

Thanks for stopping there. Much more numbers, and you would've lost me LOL

mdc5150 wrote:So for SFIC you have your change or user keys depending on your choice of terminology, and a control or core key to remove and place the cores.

So this terminology: change or user keys ....versus.... control or core key

Control makes sense - it gives me 'control' of the core. Easy enough to remember.
But it's the CHANGE key one that always gets me. lol. For some reason I always
tend to think this one will allow me to 'change' out the core. I obviously don't work
with it on a daily basis. So I guess I'll just stick with user & control. lol

-------------------------------------------------------------------------------------------------

I plan to begin impressioning these. I hope to be able to reliably create a user & control key.
So my question: Do you think that having a deeper understanding of how these are pinned
up (as you do) will help me in regards to this? Also, do you see me running into problems?

I'm assuming I'm bound to hit one of the sheer lines. But either, at will? Might be a different story.
Just trying to shorten my learning curve before it begins. lol
" Enjoy the journey AS MUCH as the destination."
http://www.youtube.com/Oldfast911
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mdc5150

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Post Sun Mar 09, 2014 4:39 am

Re: Interchangeable core general knowledge....

I can't believe this got stickied, thanks Xeo!

Mike, I can't imagine how you would impression them any other way than only turning the key to the left and going for a key to turn the cylinder. If you turn to the right you will be trying to impression 6 or 7 chambers most likely with 4 pins in each chamber, on top of that shooting for only one of three shear lines. Yes three because you would have the control, change and master. I can send you a well used WE core with your package when it goes out on Monday.
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magician59

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Post Sun Mar 09, 2014 5:20 am

Re: Interchangeable core general knowledge....

Here's a link to a pinning calculator I made.
https://drive.google.com/file/d/0B-lKIU ... sp=sharing
Nemo Malus Felix
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Oldfast

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Post Sun Mar 09, 2014 5:34 pm

Re: Interchangeable core general knowledge....

mdc5150 wrote:....Mike, I can't imagine how you would impression them any other way than only turning the key to the left and going for a key to turn the cylinder. If you turn to the right you will be trying to impression 6 or 7 chambers most likely with 4 pins in each chamber, on top of that shooting for only one of three shear lines. Yes three because you would have the control, change and master. I can send you a well used WE core with your package when it goes out on Monday.


Well shit, lol. Sounds like quite a clusterfuck of possibilities.
Maybe I'll just approach this as 'a fun thing to try'. lol
We'll see how it goes I guess. Thanks for the info!
" Enjoy the journey AS MUCH as the destination."
http://www.youtube.com/Oldfast911
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jeffmoss26

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Post Tue Mar 11, 2014 7:57 pm

Re: Interchangeable core general knowledge....

I just came across this video, an excellent overview:

macgng: i just thought the cat was a real tiny bear
GWiens2001: Great video! Learned a lot about what fun can be had with a forklift and a chainsaw.
pmaxey83: but i first have to submit the proper forms for a new hobby to my wife
xeo: i root for the kernel

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