Abloy classic and trying the ‘reduced contact area blank’

In a couple of weeks Han and I will be giving a two day impressioning course in Spain. It is going to be the second course we organize for the Spanish APECS locksmith organisation in nine months. Last time we gave a very successful course on bumping Spanish locks (a small test proved around 80% of the pin tumbler locks on the Spanish market could be bumped). This time the topic will be impressioning.

successful impressioned key for 6 disc abloy camlock

One of the things I am focusing on lately is ‘advanced impressioning’. This means trying the technique on other locks then the standard pin tumbler locks, or modifying keyblanks to make life more easy or have a higher success range on high security locks.

The lock high on my wish list is the Abloy classic (PDF). As far as I know it is the oldest system that uses discs instead of pins, yet it still is (to me) a remarkably secure lock as it has a very high degree of pick resistance. Of course I had to try if I could use impressioning to open it.

My first attempt was to simply give it a try and see what happens. In this case I just took a classic key, smoothened it and filed down where I saw marks. I soon realized this was not going to work. I had absolutely no idea of the exact position of the discs on the blank and the marks kept wandering from left to right. So my second try was using a marker making some dots on the blank, indexing where the discs should be. Still this did not work well as the marks were sometimes appearing between the dots … and I ran out of blanks too …

I recently bought more blanks and could continued the challenge. My new strategy: reducing the contact area of the key. Using a caliper I noticed the spacing on Abloy classic is two millimeters (at least on the locks I was experimenting with). So I marked the blank and removed the material between the positions. For removing the material I used a fine metal saw, a dremel tool (with a diamond disc) and a very fine ‘blade file’ (knive file?). After some work I ended up with a ‘reduced contact area blank’ that looks like a comb.

abloy classic key modified for impressioning (reduced contact area)

Filing down the remaining teeth of the comb is done with a special file. This file is cut only on the thin side. Using this file will only remove material from the contact area of the file, and not from the side of the blade (like on a normal ‘full contact’ file).

I did not have a whole lot of abloy classic locks and was happy to have one padlock I did not know the key-combination of. I did have the key, but put it in a bag without looking at it. Using the reduced contact area key I got the idea I was on the right track … when the key broke off in the lock (grrr). And I could not get the remaining key out of the lock and was out of test locks….

It is a good thing Han managed to remove the key from the lock, and even though I was on the right track I was too deep on some positions.

Talking with Han, we came to the conclusion to start easy using a simple six disc camlock. As most abloy classic locks have a cut 1 (no material removed) on the first and last disc, there were only four discs to work on. And each of these discs could have a cut between one to six (as you can see on this ‘stairway’ key that is cut 1-2-3-4-5-6). This four disc lock did not provide a challenge and was opened in a couple of minutes (without knowing the code).

After this success I did buy some new nine disc padlocks, yet I still have not managed to open them. Somehow I am doing something wrong … so I would be grateful if people would share their experiences on impressioning disc (and lever?) locks in the comments or using a private message …

Of course I will keep trying and report back if I know what is needed to successfully open the nine disc version …

* Update 22/06 21:00: hyperfocus kicked in and … voila … just opened the nine disc version …
All I did was make the teeth of the key a little more thin, and filed in small steps. I must say I am pretty pleased with this success as I have not found any other info out there on people successfully opening Abloy classic locks this way …

successful impressioning on nine disc Abloy classic lock

27 Responses to “Abloy classic and trying the ‘reduced contact area blank’”

  1. NKT says:

    Nice work Barry!

  2. Remember Barry when we discussed this when I was in Dutch Open for the first time? You asked me about this and I said it is possible, but you have to prepare the blank in some way as otherwise it will not show the marks 🙂

    You figured out a nice way! Oh and by the way, Abloy Classic/Profile/Exec cuts are numberred from 0-5).

    My own idea would increase the impressioning probability easily: Just make a tensioner that is like a key that has only the tip in in the original size, the rest of the shank is cut to full (“666” key) and the shank reduced in radius by 0.5 mm. This would allow inserting a small half-section of a tube, which would take the impression. You could easily lock the discs in place with the tensioner and then rock the piece of tube back’n’forth to get the marks.

    The reason you have to file very lightly is because if you file just enough, the gate will align with the locking bar just barely and it still has some more room to move without affecting the alignment, but if you file too much, then the disc won’t allow that small minute amount of rocking as the gate goes past the locking bar.

    How much time did it take to impression?

  3. mh says:

    Wow, great job, it must be tough to get good marks and interpret them correctly; tensioning a pin tumbler lock should hold the pins much better in place for impressioning than the locking bar could grab the discs?


  4. mh, actually the locking bar really holds the discs in place. One example is when picking the ABUS locks, if you tension even a little the binding discs will not move.

  5. jos weyers says:

    So these are the new locks for the dutch impression championship at HAR?

  6. Oh and yes, Barry you are right, the spacing in Classic and Profile is 2 mm (keys are cut with a 2.5 mm wide blade). Thin Profile, Exec, Disklock, Disklock Pro and Protec has 1.6 mm spacing (keys cut with 2 mm blade).

    The reason why your key broke in the lock seems to be the fact that you cut the grooves a little too deep. Halfway of the keyblank is all that is necessary, anything else past that just weakens the key blank. I would attach the keyblank to a vise after scribing a line to the middle of inked blank and then use a Dremel with a cutoff disc or similar. Or just a thinned down hacksaw blade 🙂

    Barry, I sent you an email asking about a permission to use your pictures in my Finnish blog, I thought about writing an article about this and possibly I’m going to try it out soon.

  7. Don Las Vegas says:

    Hey Barry !

    Nice work ! I am going to give it a try I will let you know how it works out

  8. HF905 says:

    So can the fileing be done in 18 degree increments? If there is a mark I could take 18 degrees off right away?

  9. HF905, basically yes, but it isn’t always foolproof 😉 I’m going to try and make a prepared blank with my mill and if it turns out easy to do and I succeed in maing it, I’m then able to provide my skills to make a batch of blanks. This means that if someone sends me the blanks, I’ll cut for a small fee 🙂

  10. Now that I think of this, if someone has an Abloy Classic keycutting machine, all that is needed is to change the cutting disc from 2.5 mm to 1 mm wide and then recalibrate the key position in order to cut the prepared blanks 🙂 Worth trying if you have a machine and the skills 🙂

  11. Work is progressing quite good, I have almost done an arbor for my slitting saw 🙂 I’m going to use 1 mm wide saw to cut the key blank. Tomorrow I’m going to have a break as we have party at our house, but I’ll resume working on Sunday probably 🙂

  12. eyes_only says:

    You guys are all hardcore with this stuff man. There are so many professional locksmith out there (at least in the US) that are still clueless about impressioning even a Ford/Jaguar Tibbe lock. Puts them all to shame.

  13. Finally got time to finish cutting the key blank 🙂 Below is a link that show the prepared blank. I will try to impression a known combination Abloy Classic with this and see what happens. If this works, I’ll post more 🙂


  14. Barry says:

    Jaakko: Now that’s a key!

    Good luck 🙂 …. and ehrm … please post more even if you don’t get it to work.

    On a known code, if there is a ‘1’ it most likely will still mark. Just remove a little bit anyway, the mark will be gone and hopefully stay gone 🙂

  15. Thanks Barry, I will post if I make progress 🙂 I already started and noticed that inking the key helps heaps in getting clear marks 🙂 I’m trying the method you described me and I hope it works. I have already files quite much, but I hope I get it to work on this lock.

    By “number 1” did you mean uncut key, as in number zero cut (Abloys cuts are numbered from 0-5)?

  16. Barry says:

    Jaakko: Yes, I meant a ‘0’ when I wrote ‘1’.

    Good luck 😉

  17. Okay, one test has now been completed and shows promising results although I did not succeed. The ink showed easily marks and I think I continue using it. The problem with this known-combination was that it was not known 😀 I think my pinning kit had some discs mixed as the key was not looking like it should, so I took the cylinder out and verified that I was on the right track and only one disc position was cut too much: a zero disc in the middle of the pack!

    So just as you warned Barry, I walked into this zero disc trap head first 😛 I think the problem was that I took pretty heavy cuts and thus filed it too much on the first time and after that the test went downhill.

    Maybe I should train myself first on an easier lock like a small camlock, as this was 11 disc door lock 😀 Yes, I did a dive in the deep end of this thing 😛

    Also worth of a note is that this is the first lock ever I have even tried impressioning, so I’m quite happy about my progress; Abloy as the first try 🙂

    I’m out of Abloy Classic blanks and have to think where I get more of them.

  18. mh says:

    Use round brass and your new mill? %) mh

  19. mh, might try that, but I suspect that brass is too weak and breaks at some point. Have to try though 🙂

  20. I tested using brass (360) as the key material and just as I expected, it is too weak to use. I tried it on a 7 disc cam lock and the key warped from the front at the point where is the first zero disc (free rotating). This in turn means that the front disc turns too much (the gate goes past 90 degrees) and you are unable to use the key even with proper cuts.

    So, now I need a source for Abloy Classic key blanks, preferably original Abloy blanks, but JMA and Silca blanks would be nice to test too 🙂 Anyone out there who could help me? I’m not able to buy any of these blanks in here.

  21. Barry says:


    Just received a box of new Abloy Classic messing silver blanks. A proposal is in the mail for you 😉

  22. I think you meant nickelsilver 😉

  23. Barry says:

    Jaakko: Ehrm … yeah … nickelsilver …


  24. FlyingDisk says:

    I’am writing not esactly because of this post,sorry for this.
    When I searched abloy locks I saw the “axira” lock. I see you have a great experience in locks and picks, so I tought you write maybe about this lock. And about the Mult-T-Lock’ MT5 too. I had seen the post about it earlier, but how I see you didn’t write more about it nowdays. So if you have enough time, and others are interested in it too I would be pleased if you wrote about these locks. Otherwise congrat. for the blog. It looks like as a professional site :D.

  25. […] how to tackle the system/ Together with Jord Knaap they improved on Barry Wels his ‘reduced contact area‘ impressioning technique for disc-locks. They found a way to get better marks and make the […]

  26. nick says:

    does anyone know how to open ilco precision 54000 series without destroying the lock?
    I have the guard key
    thanks a lot!

  27. jim says:

    This is so cool I am working on this with my hand made blanks. ON a mill cut stock. I just got into the Abloy aspect of the hobby. I spent too much time volunteering @ DEFCON with TOOOL. I made it home and have been trying to impression the classic since I got back. Barry would you sell me some blanks? they are very rare here in the US I can find disclock but no classics.

    No luck yet but I am working on my skills.