Making A Car Key From A Ratcheting Wrench

Car keys these days are remarkably complex beasts. Covered in buttons and loaded with security transponders, they often cost hundreds of dollars to replace if you’re unlucky enough to lose them. However, back in the day, keys used to just be keys — a hunk of metal in a mechanical pattern to move some levers and open a door. Thus, you could reshape a wrench into a key for an old car if that was something you really wanted to do.

The concept is simple. Take a 12mm ratcheting wrench, and shape the flat section into a profile matching that of a key for an older car without any electronic security features. The first step is to cut down the shaft, before grinding it down to match the thickness and width of the original key.

The profile of the key is then drawn onto the surface, and a Dremel used with a cutting disc to create the requisite shape.  Finally, calipers are used to mark out the channels to allow the key to slide into the keyway, before these are also machined with the rotary tool.

Filing and polishing cleans up the final result to create a shiny, attractive ratchet wrench key. Even better, it does a great job of opening the car, too.

Similar machining techniques can be used to duplicate a key from just a photo (something I did back in 2019 to prank my friend). Alternatively, 3D printing can be great for reproducing even high-security keys. Video after the break.

45 thoughts on “Making A Car Key From A Ratcheting Wrench

  1. Really cool hack, but bad for overall longevity of the lock cylinder. Keys are made of softer metal for more reasons than just ease of cutting: the cylinder pins will outlive the key. Wrenches are made from chromoly steel, far harder than the pins. If the wrench key is used daily, you’ll be changing that lock cylinder often.

      1. I can’t imagine that’s anything other than a decorative plate, not a hardness plate. Even if it is a hardness plate, it’s still only tens of microns thick, as opposed to the wrench which is likely equivalent or harder and so it’d wear down the entire thing.

    1. Not true.
      As long as the materials are dissimilar enough it will be OK.
      Hardened and polished steel key with brass (or softer steel) levers in the lock is OK.

      About the worst you can get is same materials. Soft steel on soft steel, or brass on brass, and there are plenty (too many? of such keys too.
      The hardest material must be smooth, or it will start acting as a file on the other part.

      And if it costs “Hundreds of dollars” to replace your car key, then it is not because the thing is complex or difficult to make. The only reason it cost so much is because you have no choice and they know it. I wish there were laws against such practices. Sigh.

    2. You are correct. Almost all keys are made of chrome plated brass. Don’t believe me? Take a magnet to all your car and house keys and see how many stick. I have a 2005 jeep wrangler. These wetre made with very poor metal in the lock cylinders. When the jeep is started you you just pull the keys out of the ignition with the vehicle still running. Try it if you have an older jeep.

        1. *Sigh* I’m an electrician at a factory, lots of ‘highly trained operators’ running million dollar machines. I’ve had two so far ask me why the vaccine made them magnetic followed by a demonstration with a key. After I showed them that brass keys do not stick to a magnet I was told “maybe you are using the wrong type of magnet.” So as an electrician I am clearly the expert on vaccine related magnetism but not regular magnetism…

      1. I have keys made from plated brass and some frome plated “white” metal. The plating seems not to be nickel, as nickel is supposed to be ferromagnetic. So perhaps it is chrome.
        I have one steel key, from wafer-lock type bike lock chain.

    1. It’s not even close to the same. This guy’s car isn’t accessible anywhere in the world and a Google account is. Cars are protected by much clearer property laws. Finally, if you really wanted to steal that old Datsun, you ‘d never go through the tedium of making a key based on a picture. You’d just hotwire it. Not even close.

    2. More accurately, a video of you typing in your password without showing the username.

      If someone copies the key from the photos or video, it won’t do them much good unless they get physical access to the vehicle, and with an old vehicle like that you don’t really need a key to get it started, anyway.

      1. Well, the steering column lock still needs the lock cylinder to release the steering wheel. Steering column locking was the second theft deterrent system after the ignition lock cylinder.

          1. Early Datsuns used a lot of SAE hardware, and some very confused bolts with sae threads but metric heads. I’m not sure why. I’m guessing production issues after the war?

  2. Very nice and themed hack. However, it will be problematic to find a nice looking wrench key without crome plated surface. So, after making a key you will definitely need a chrome plating to make your job look consistent.. Crome iIntegral part of many restoration, backporting or upgrading hacks..However, you can’t find anything on HaD about so required simple DIY crome plating. Yes,you are right, that is impossible in hacking world narrative. “Crome plating is bad”, “You don’t need that bad, bad crome pating at your garage”. Hilarious.

  3. About 99% of keys and pins/wafers are made from nickel-silver (80% copper, 20% nickel, 20% zinc). The keys are softer and designed to wear first as is it much easier to cut a new key from specs than it is to re-pin/wafer a lock cylinder. A well-made lock has tolerances in the .001’s of an inch and it is not uncommon to shim up a worn key with a sheet of paper while duplicating, or pull out the micrometer/depth gauge to cut it back to original specs.

    The only exceptions I can think of in these modern times, off the top of my head, are lever locks (like safe-deposit boxes) which are a soft steel blank and a Schlage “L” keyway, which is factory ordered and cut on stainless due to its very narrow profile. I have seen keys made from aluminum, copper, brass, steel, plastic, fiberglass, pot metal, just about everything.

    And yes, I have cut keys from photos plenty of times. I always encouraged my clients to NOT wear the big “janitor” keyring on their belt, especially at some of the more sensitive facilities, due to how easy of a process it really is to anyone with the gumption to do it.

  4. I doubt anyone saying that it is hugely labor intensive to re-pin a lock cylinder has ever done it. It is extremely easy. And fast. Not saying cutting a key int easy as well but re-pin a cylinder AKA “change the locks” can be done in less than 5 minutes by even the most unskilled locksmith. Or, like, a 12 year old learning to pick locks. Hypothetically.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.