Submitted by: Karen Wakowski
A bump key is a very special key that can be made out of
key for a certain lock: for example, if you’ve got a regular key for a Schlage C-keyway (the most common) lock then you can make a bump key out of it that will open
Schlage C-keyway lock, and you can do it with just a regular hand file, that’s it!
How Bump Keys Work
A normal key works by raising the pins inside a lock’s keyway to a certain height. Those pins have been individually cut to different heights such that if they’re all raised to where they’re cut (called the “shear line”) such that they’ll allow the cylinder to turn, the lock will open. The key raises these pins by having various ridges and valleys cut in it such that when it’s fully inserted into the lock it raises all the pins to the correct height.
A bump key works by “bumping” those pins (which are spring-loaded) straight up very quickly while, at the same time, you apply a slight turning force to the key, and during that split second that the pins are in the air, if you time it right (it’s not hard), the shear line is clear and the cylinder will turn, thereby allowing you to open the lock!
What Types of Locks Will This Work On?
Almost all of them. The type of lock bump keys work on are call “pin-tumbler” locks, and the great majority of locks in modern use in the world, and almost
of the locks you see in the U.S. (Masterlocks, any other padlocks, regular front-door deadbolts, storefront locks, etc.) are pin-tumblers.
The only catch is that you need to use a key, when you make your bump key, that is the same keyway as the lock you want to bump open–this is very easy, as most major brands only have a few common keyways, and if you cover just 4 or 5 major keyways, you’ll be able to open 90% of all the locks out there. The most common door locks are Schlage and Kwikset, most Schlages are C-keyways and Kwiksets are almost all the same keyway, and the most common padlock is Masterlock, most of which use the same keyway. If you’ll get a Schlage lock, a Kwikset, and a Masterlock, and then use their keys to make bump keys, with just those 3 keys you’ll be able to bump open over 80% of all the locks in use in the U.S.
How To Make a Bump Key
1. Get your key.
2. Get a small round file.
3. A vice will make this a
easier, but it’s not absolutely necessary, you can just hold the key in your hand while filing if you don’t have access to a vice.
4. Find the lowest valley amongst the biting on the key.
5. Using that point as a reference, file down all the other valleys (not the points, don’t file the whole key down) to that same height.
6. It wouldn’t hurt to use some 300 grit sandpaper to smooth over the rough spots on the biting so the key slides smoothly in and out of the lock. That’s it, you’re done. I told you it was easy.
How to Use It
What you do is insert the key
all the way into the lock that you want to bump (let it stick out of the key hole maybe a couple millimeters or so–slide it in so that there’s one ‘click’ left before it’s all the way in, if that makes sense), then you’re going to whack the key from the back with something hard (the handle of a hammer or screwdriver works great, a shoe will work too) and simultaneously turn the key the direction it would normally go (turn it just a slight split second after bumping the key). You may have to do this a few times before the lock opens, but it
work. If that key will fit in the lock, then you absolutely can bump it open.
About the Author: I’ll SHOW You How to Do It: Video and Diagrams If you’re still confused or just want to make sure you’re doing it right I’ve got a fantastic article called
bump key how to
with a video where I show you precisely how to make a bump key by hand in just a few minutes and then demonstrate it on a lock, plus there’s a PDF file you can read that goes into much more detail on how to make bump keys.