Swiss Army Keys


This isn’t a hack that shows you how to start a car without the keys. It’s a way to ditch the bulky keyring for a set of fold-out keys. [Colonel Crunch] removed the blades from the pocket knife and replaced them with the two keys for his car (one is ignition and door locks, the other opens the trunk). He didn’t take pictures of the process, but he did link to this unrelated guide on how it’s done.

About one minute into the video after the break we see each step in the build process. First the plastic trim is removed from either side of the knife. The blades are basically riveted on; there’s a pin which holds them in and either side of it has been pressed to that it can no longer move through the holes in the frame. To get around this one side is ground off with a rotary tool, and the pin is then tapped out with a hammer. The removed blade/scissors/tool is used as a template to cut the body of the key down to size and shape.  The pin is then hammered back into place before putting the plastic trim back on.

[via Reddit]


  1. Ren says:

    Neat, but I’m concerned about the weight this puts on the lock cylinder.
    Years ago, a locksmith (fixing my old ignition switch), warned me that too much weight
    on the key ring was a common source of failure.
    He also warned me against using WD-40 in the cylinder.

    • Ren says:

      P.S. once the scales (plastic sides) come off the knife, they will keep coming off, unless a strong adhesive (epoxy?) is used. DAMHIKT (Don’t Ask Me How I Know That).

      • Ren says:

        And forget about getting these keys through TSA (airport security)!

        • tomas316 says:

          As long as your cut off the blades, you can take your swiss army knife on the plane. The TSA finds it and looks so happy, like its the first thing they did all day, then you tell them there’s no blade, then they go back to looking like their wasting their life away.

          • cde says:

            Cork Screw is still on though. That will stop you.

          • zarnochwf1 says:

            In response to the corkscrew thing, I flew back through SFO with a corkscrew that had an attached razor knife to cut wine labels. I had forgot it was in my laptop bag, since I bought it on the trip.

            Nobody cared/said anything, but someone had their nail clippers confiscated in the same line.

    • It will DEFINITELY cause premature ignition lock failure. This is a Bad Idea(tm). It is wisest to keep your keys mounted such that you can take off just the key you want and put it into the ignition.

    • Leif Burrow says:

      I’ve always had a lot of keys on my keyring. It’s definitely heavier than that little knife. I’m always being told this is going to give me a problem but my life just happens to involve using a lot of keys. If I separated them I am sure I would forget or lose some.

      I’ve put about 200k miles on my Jeep with no ignition issues yet. Hypothetically, if it failed at this point was it necessarily because of the weight or just because it is old and heavily used? The same for the about 100k miles each I put on my previous two vehicles.

      • RoadWarrior222 says:

        It was kinda the “Getting away with it” on Chrysler product ignitions that lulled me into a false sense of security about doing it on everything else…. though their problem would be that on a 100k+ one, you could probably start it just with the blade of the penknife, no need to swap the key in.

      • matt says:

        I have half a dozen keys on my ring along with a keyless entry, and the inigition in my ’99 Jeep Cherokee no longer retains the key when it is started after 145k miles.

  2. omnivore says:

    What an incredibly clever way to make sure that your keys will be confiscated every time you fly.

  3. TMM says:

    also only works for cars that are prehistoric and only require a key shaft.

  4. Kelly Petlig says:

    I hesitate to think what the police accusations will result from this.

  5. messmaker says:

    Neat idea, for all but the car keys for the above reasons. I might have to do something like this.

    I hope having a show on HBO will help him make next months rent…

  6. RP says:

    That rigid torque arm is going to turn off the ignition if you tap the brakes hard.

  7. hudson says:

    I did the same thing with a Crank Brother’s bike tool since I was tired of the clanking of my key ring. There was enough space to retain the 2mm, 3mm, 4mm and phillips screwdriver as well. I haven’t had any problems with TSA security, either, since there are no blades on the tool. Photos:

  8. Bob Fleming says:

    I’m just watching re-runs of MacGyver – he’s been doing this with locks for years! :)

  9. ChalkBored says:

    It doesn’t look at all like you’ve stolen that car.

  10. Ok so who is going to be the first person to jam a remote key fob into this sucker?

  11. RB says:

    Make sure you take the transponder out of the ignition key otherwise the immobiliser won’t let the car start.

  12. Hirudinea says:

    I like the fact that he left the corkscrew on the knife, you have to admire a man so committed to drunk driving.

    @ Hudson – Your key knife (is that what this thing is called) is far superior.

    • mandoholic says:

      The weight on the lock and the corkscrew were the first things I noticed too. I wouldn’t want to do it due to the stress on the ignition lock, but having the corkscrew almost makes it worth it. Still… it’s a pretty cool idea even if it’s got some serious drawbacks.

  13. Eric says:

    Better make the corkscrew unavailable while the car is running.

    • Rob says:

      From the photo, I’d say the corkscrew is pretty much “unavailable” while the key is in use. Considerably more unavailable than the various bottle-cap-popper key fobs sold at C-Stores and souvenir shops everywhere.

      But later, you’ll be glad you left that on there: modifying Swiss Army knives is thirsty business.

      Now, on to replacing the saw or magnifying glass with a memory stick.

  14. I will agree with RB that if your car uses a RFID tag this hack will not work unless you harvest the chip from the old key. IF the tag is in a glass ampule then you will be in luck just put the head of the key in acetone and let the plastic dissolve. you might have to replace the saturated acetone a few times until all the plastic is gone.
    Just be ware that if the tag is not in a glass ampule the acetone will dissolve the enamel coating on the antenna wire of the tag and you will be SOL. Good luck.
    once you have the tag you can use a Dremel to carve out a notch on the inside of one of the handles close to the end where the key is.
    Beware that you more than likely can only do this for one car the tags might inter fear with each other.

  15. RoadWarrior222 says:

    BTW I think there’s a similar in concept commercial version of this, you can get for your elderly relatives, to put doorkeys in when they start having issues with a weak grip and need the leverage to turn them.

  16. HC says:

    This is so much better than that overpriced piece of SkyMall crap known as the “Keyport Slide.”

  17. x says:

    I would rather use my phone as my keychain

    • matt says:

      Good luck getting back in when the battery dies in either the phone or lock. I also question the security of the device when they wont even state which encryption algorithm or authentication system it uses; let alone subject it to peer review.

  18. vonskippy says:

    Dork Factor set to EXTREME.

  19. CorrosiveOne says:

    I love it!

    So what if its not necessarily good for the lock, we do plenty of things that are not good for us or the tech in our lives.

    Have fun with it for god sakes! Great job guys!
    Although, do be careful with the police lol….

    Oh… I’m just starting my friends car with a swiss army kn—-key!

  20. SMTHacker says:

    Yet more content lazily pulled from reddit

  21. Not_On_Fire says:

    thumb print reader RPI nuff said

  22. matt says:

    Why does he call it “art” in the video? Why is it in black and white? Seems like this guy is desperately trying to be a hipster. I swap a PC component is that art? How about replacing a part on my car? What about installing a extra electrical circuit in my home?

  23. Waffles says:

    OMG people, its a sweet ass hack/build. I’m sure that for all the more he drives (clearly not much) it will be fine. FFS. Just enjoy the novelty.

  24. quityerwhinin says:

    If you don’t like it, are afraid that your lock will wear out faster, or that the nanny state government will throw you into prison and confiscate your keys DON’T DO IT. Otherwise its a neat idea

  25. HackJack says:

    all the key replicas work on the first try?

  26. Valient says:

    I have a used 2001 impala. My knife came with a built in key for it. Its called a knife.

    Should i fix the ignition??

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


Get every new post delivered to your Inbox.

Join 98,062 other followers