what are bump keys ? pros and cons

[hillbilly21]

hey, i'm new to all this and i might have just not looked in the right threads. but could someone explain the bump keys to me with the pros and cons thanks. cody

[LockDFTR]

Hey Man,

A bump key is a specially modified key, that can make it possible to open many locks using one key, and a special technique.

Unfortunately, I believe that the discussion of bump keys is only allowed in the advanced section of this site. Try looking it up on you tube. I am sure you will find more info about the subject than you would actually care to know. Happy hunting

[n2oah]

Pros:Quick and easy opening for most locks
Cons: Damage caused by bump keys is usually easily detected, prolonged use of bump keys can damage or destroy locks.

[MacGyver101]

Unfortunately, I believe that the discussion of bump keys is only allowed in the advanced section of this site.

No: they're fair game for discussion in the open forums. There's been a lot of discussion of them in the past... many of the old threads should give you a good start on the info you're looking for.

[hillbilly21]

ha ok thanks guys you pointed me in the right direction sorry if i put this up in the wrong spot like i said i'm a newbe ha. but thanks again

[Satan130]

Pros:Quick and easy opening for most locks
Cons: Damage caused by bump keys is usually easily detected, prolonged use of bump keys can damage or destroy locks.

really? what i had heard was police were having an extremely difficult time accurately estimating the number of bump key related thieveries because the key left little to no remnants of it's existence, and knowing how a lock works, i can't think of why it would.

where did you here that from?



and actually, because of bumpings recent publicity their have been more and more bump proof locks, but if you have a bump key for a brand that isn't bump proof, it is a complete skeleton key.

on the other hand, I'm a less then reliable source, so take everything i say with a grain or two of salt.

[MacGyver101]

. . . because the key left little to no remnants of it's existence . . .

There have been a few good studies published, looking at the marks left by "bumping" from a forensic standpoint. (Unfortunately, I don't have any good on-line references that I can point you to at the moment.)

The primary markings are from where the key bow strikes the face of the cylinder. Repeated bumping can also distort the base of the bottom pins (in a manner that is inconsistent with normal key insertion) and, in extreme cases, the fronts of the chambers can be distorted from repeated striking of the bottom pins. Having said all that, the only studies I've seen have shown photographs of relatively new locks... I suspect that the signs start to become far less distinct on a well-used, 10-year-old front door lock. (And, CSI shows aside, the local police simply don't have the resources to have every lock dismantled and forensically examined after every break-in... so that also plays a role in the reporting figures, I'm sure.)

[chev49]

Most police in real life around here, are going to think you left your door unlocked & not even consider having the lock removed & examined.
Using a bump key to get a door unlocked is a good idea cause its fast. It's not something that's used everyday, so what little dinging the key does inside, doesn't really matter. I haven't tried this, but someone with a lot of time should take about 20 locks of the same brand, use a regular key on 10 of them and a bump key on the other set and determine the mean time between failure of the sets. (Should have done something like this - with govt funding - in grad school -- then I could have written up a paper with charts, bell curve, and the like)

[reacher]

not as easy as the publicity suggests , the keys work very well on certain configurations of pins , and not on as many locks as the site of one of the main sellars of these keys claims , haveing said that they do work , in my experiance if it can be bumped its useually not that hard a lock to pick , verdict , very hit and miss , not for serious locksmiths , learn to pick .

[zeke79]

The top pins cannot be overlooked. In many cases, the top pins will show quite rapid wearing on the sides of the pins appearing as linear markings or even pitting of the pins in my "home experiments" which are far from laboratory conditions. Even with my home not having lab conditions, I feel it is more similar to real world scenerios.

I believe I have read about a paper put out by Chris Belcher on the topic but have not read it. If memory serves me, it was either mentioned on clearstar or I had heard similar info when discussing my results with a close friend of mine who is a UK lockie.

[patrickson]

Damage caused by bump keys is usually easily detected

Skilled "bumpers" can open locks with 1-2 bumps, and that little damage is not easy to detect, especially on an old lock.

Bumping is a very clever idea, but it lacks the finesse and "heart" of lockpicking. But I must admit that simply the fact that locks can be opened by such a "stone-age" technique is really amazing!

[yoyoboy]

Here's a tip: go around to all of our doors and bump them a few times. That way, even if you do leave your door unlocked and your house gets robbed, you can get your insurance company to have the locks inspected.
Note: I am not responsible for any use of this information in a fraudulent manner, or damage caused to your locks. FURTHERMORE if you are a member of this forum, what the hell are you doing with bumpable locks on your door!!!?

[sugurfoot]

A b ump is just another means of opening a lock, If your good you can do it in 1 or2 trys, But picking is more fun.

[Engineer]

Bumping a lock can be either really easy to tell, or almost impossible, it depends on the technique you use.

One technique has the shoulder of the key removed, for the minimal movement technique favoured by TOOOL it seems. The leaves very few traces and may even be impossible to say with any certainty, even with forensic microscopy. It will depend on some things I don't want to go into here.

Obvious damage is left behind by the more usual bumping, where the key has to be pulled out after each bump a little. Here the shoulder of the key is not removed and it hits the face of the lock, usually leaving marks on the face of the lock that is a dead give-away to people "in the know". Most Police Officers do not seem aware of this technique, but it will depend enormously on where you are, which Officer is investigating your case, etc.

If you believe you are the subject of bumping, then INSIST to the investigating Officers that the lock is taken for forensic microscopy. They will need to look for specific striations (they will know what that means).

[raimundo]

I have no doubt that Zeke is right about locks used for bumping practice, however, if someone comes up to your door with a smooth bumpkey, (one that has been used a bit, not a fresh cut one) and give it a light tap, one time and opens your door, there is not much evidence to see. The shoulder of the key will strike the face of the plug, but thats just where normal wear also hits it. If this area is disturbed in a larger way, the likely reason would be impressioning a key, not bumping
Han Fey and Barry Wels have tested a lot of european locks with spool pins and found that bumping will defeat some high security locks that are difficult to pick.

Certainly bumping can damage locks, but a skilled bumper can open them without visible damage.

Key impressioning will cause much more marking on the face of the plug.