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Instructions On Creating A Bump Key.


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#1 ArizonaLizard

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Posted 27 September 2006 - 05:02 PM

Ok.... Let me first say that you should consider purchasing the keys from this site as your first choice. In my opinion, the 20 bucks you will spend is less valuable than the amount of time and energy you will spend (properly) creating your own.

With that being said, and you are really broke, or just very mechanically inclined, or bored, or for whatever reason your heart is set on making your own, let's get started.

First, the things you will need:

1. A blank key. You may obtain this from Wal-Mart or your local hardware store. Please ensure that it is the proper form for the lock you will be bumping. Each company creates their own keyway for their locks, so a Weiser blank will not work in a Kwikset lock. (You may also use an old key, but if there is a deeper cut in the pattern, it may make this method more difficult. I recommend a blank uncut key.)

2. A deadbolt lock. You can use the one off your door, if you wish, but I caution you that you will be disassembling it entirely. Either ensure that you are very detail oriented, or just go spend 10 bucks on a deadbolt from Wal-Mart.

3. A TRIANGULAR file. It is possible to use a square, but a triangular works much better, as it will create a more aggressive angle in the key notches.

4. A thin, pointed file. This will be used to insert into the pinholes, so it needs to be very thin and circular. Most hobby sets have one. You can use just about anything, but it needs to be able to scratch and mark the blank key.

5. Needle-nose pliers, very small flathead screwdriver, other miscellanous household tools.

In this model, I will be describing the method using a Kwikset deadbolt.

Begin by disassembling to lock to the point where you only have the keyway assembly. This should consist of the point where you enter the key into the lock, the housing (just the steel cylinder that holds the keyway, pins, and springs), and the turnrod out the back.

If you examine this cylinder, there should be a ridgeline on the back, capped with a silver slideplate or other cover. This is the area that the pins are housed in the lock.

If this is just a guide lock that was purchased for the purpose of creating a bumpkey, then just pop the cap off with the pliers or screwdriver, and dump out the springs and pins.

If this is a lock that you plan to REUSE (like, say, the one off your front door?), then you want to use great caution in removing the slideplate. Make sure you do this in a well lit, clean area where, so that when you drop something small and hard to see (cause you will), you can find it.

The purpose of the cover/slideplate is to hold the tension springs in place. These springs are designed to keep pressure on the pins, and are important to the function of the lock. When you remove the plate, they have a tendancy to POP up, and sometimes out, of the lock.

After you remove the springs and place them in a safe place, prepare to remove the pins. You will do this by placing your finger over the back (furtherest from the key entry) 4 pin holes (the number of pin holes can vary), and dump the 2 pins from the front hole. The order of these pins is VERY IMPORTANT, as they determine the pattern of the key used in the lock. So, you want to ensure that the pins from hole 1 go back in hole 1, and also that 2 pins from each hole go back in the proper order, top pin on top.

A hint is that the top pins from the holes will be the same length, while the bottom pins will be of different length.

Now that you have removed the pins and the springs, you should be able to freely spin the blank key in the cylinder.

Ensure the key is fully in the cylinder, and upright. Take the pointed file and insert into each pin hole, and wiggle it around. When you remove the key, it should have marks showing you the exact spacing needed for the bump key. (At this point, the shoulder and tip of the key should NOT be modified. That comes later.)

Take the triangular file, and begin removing metal from the key in the marked spots.... Reinsert the key as neccessary to remark, and ensure that you are on track.

You want to file down to the lowest spot on the key that DOES NOT enter the grooving in the key. If you enter the grooving, it can cause the key not to work.

Once you have the key complete, it should have the pointy look that you have seen on other keys.

Now is the time to file off the tip of the key (make sure that the key maintains an angled slop on the tip, for ease of entry) and the shoulder.

It is important that you understand why you have to file the tip and shoulder, and how it works... By understanding how and why it works, you will get a good idea of how much to shave off.

The principle used is that of a pool game. In pool, the cue ball strikes the target ball, it transfers the energy to the target ball. The cue ball stops, and the target ball moves...

Now, remember those two pins in each pin hole of the lock? Well, in this method, the key will act as the pool cue (the stick), the bottom pin is the pool cue ball (the white one), and the top pin is the target ball.

The key, in its current state (shoulder and tip intact), allows the pins to go as far down as possible when it is fully inserted.

But we want to "bump" the bottom pin with the key, and cause that energy to transfer to the upper pin. That way, the upper pin travels up, while the bottom pin stays on top of the key. This creates a gap between the pins, which simulates the condition of entering the proper key.

The way we do this is to remove some of the shoulder and tip. Now the key can actually go further into the lock than it could when you created it.

If you do push the altered key into the lock, those bottom pins are no longer at the bottom of the notch. They are being forced upwards by the back of the notch. Now, the secret is: They don't need to be moved far. As a matter of fact, you don't want them to move far. If they move to far up, they may close that all-important gap.

So, when we shave the tip and the shoulder, we only want to remove just enough to make that bottom pin slide up the slightest bit.

When we combine that with a quick, light amount of force on the key (like striking the white ball with a short, quick stroke of the cue stick), we will get the bottom pin to move up a short bit, then stop, while the top pin will continue up.

Now, to test your bump key...

Place the top and bottom pins back into the pin holes, but DO NOT reinsert the springs and the coverplate.

Now, place your bump key all the way in, then slide it back the smallest fraction. This will cause the pins to settle to the lowest point. Now, use your finger to quickly tap the key in. You should see the top pins FLY out the top of the pin holes. If not, your key is not properly spaced, or you need to remove a bit more of the tip and/or shoulder.

The two most important things in a bump key design: The spacing and angle of the notches, and the shoulder/tip shaving.

By using the above listed method, you will have an excellent guide to the spacing and angle.

P.S. After you notch your key, but BEFORE shaving the tip and shoulder, consider makeing a copy or two at wally world. That way, you have a spare in case you overshave your key.

#2 LockPickIt

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Posted 08 December 2015 - 11:20 PM

Bookmarked this page. Very well written and high quality post. Will read it later as I'm on the road atm lol



#3 LogiGoi

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Posted 09 December 2015 - 09:00 AM

I don't know what to say but, dude you're a pro! Do you happen to make bump keys for a living?



#4 TanVanMan

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Posted 12 December 2015 - 03:17 AM

Wow.. interesting and very detailed. This is really a good help for those who want to make their own bumpkeys. For me, I will just have to purchase mine lol..



#5 LogiGoi

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Posted 12 December 2015 - 04:35 AM

Wow.. interesting and very detailed. This is really a good help for those who want to make their own bumpkeys. For me, I will just have to purchase mine lol.

What would be the set of bump keys you are going to buy???



#6 TanVanMan

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Posted 13 December 2015 - 05:20 AM

What would be the set of bump keys you are going to buy???

I haven't decided yet. Just saying if I am to choose between making my own set of bump keys and purchasing, I prefer purchasing lol :-)



#7 LogiGoi

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Posted 13 December 2015 - 07:38 AM

I haven't decided yet. Just saying if I am to choose between making my own set of bump keys and purchasing, I prefer purchasing lol :-)

Well since were both new to this then obviously the ones that are being sold are much better than the ones that we will be making just in case...hehe



#8 redcity

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Posted 13 December 2015 - 11:32 AM

Well since were both new to this then obviously the ones that are being sold are much better than the ones that we will be making just in case...hehe

Be confident, give it a try unless you have time to get away with bumping otherwise purchasing them is a good option



#9 LockPickIt

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Posted 29 January 2016 - 12:02 AM

I don't know what to say but, dude you're a pro! Do you happen to make bump keys for a living?

LogiGoi good question. In my place you can never find a service "key bumping" or anything close to it but "lock smith"