Bump Proofing?

[Jeckel]

How would you re key a lock in order to prevent lock bumping, and is there a way of seeing if some one has attempted to bump a lock?

[datagram]

You can't re-key a lock to prevent bumping. Bump prevention has to be a part of the design of the lock via specialized top pins, pin chambers, or various additional security mechanisms (such as a sidebar).

Bumping leaves various forensic evidence, visibly on the top and bottom of the keyway where the should contacts the plug. This can be mitigated by using a glue gun shoulder to the bump key. There is also distinct evidence on the pins inside of the lock, of course.

dg

[Wolf2486]

They make various specialty pins you can rekey your lock with to prevent bumping. Also, if you can find a pin from another brand of lock that exceeds the 9cut position for your brand of lock, and if there is enough room on the key to file down that position just a little, you can make the lock virtually bump proof as most bump keys are cut all to 9 depths... this pin would essentially be a 10-depth.

[mitch.capper]

Short of buying a lock that doesn't use the standard pin tumbler setup you can't really become bump proof and there is no pin I have heard of that you can add to a lock that can promise that. As said you can try to defeat a bumper by making things harder for them but if you have a pin tumbler there is a good chance there is a way to bump it:)

[Engineer]

Buying a lock that is specifically bump-proof would be best. If that is not an option, then you can make it harder to bump (but not exactly proof) by repinning the second pin from the front and the second pin from the back with a "9" pin. I would also make the last pin a "1".

This only works because most bump keys are cut to "999" depths. When the key is hit, it makes the pins jump up. If one or more pins are already at a 9 depth, then the moment those pins jump up like the others, they are preventing the cylinder from turning.

This can be got around by artifically cutting the cutting one depth deeper to make a "000" key, however that is the reason for making the pin deepest in the lock the shallowest cut. The key then has to provide enough "kick" to lift that last pin to the highest level, while the cylinder can only be turned when the 9 pins are quite low. This minimises the "window of opportunity" when the cylinder will turn to a very small fraction of a second and make it as difficult as possible to bump.

The lock will still probably give in to an electric pick relatively easily, but you will have made it as difficult as possible without actually getting a bump-proof lock specifically.

There is at least one treatment being sold that claims to make locks bump proof, but I have never used it, so cannot vouch for it personally.

[mcm757207]

Buying a lock that is specifically bump-proof would be best. If that is not an option, then you can make it harder to bump (but not exactly proof) by repinning the second pin from the front and the second pin from the back with a "9" pin. I would also make the last pin a "1".

This only works because most bump keys are cut to "999" depths. When the key is hit, it makes the pins jump up. If one or more pins are already at a 9 depth, then the moment those pins jump up like the others, they are preventing the cylinder from turning.

This can be got around by artifically cutting the cutting one depth deeper to make a "000" key, however that is the reason for making the pin deepest in the lock the shallowest cut. The key then has to provide enough "kick" to lift that last pin to the highest level, while the cylinder can only be turned when the 9 pins are quite low. This minimises the "window of opportunity" when the cylinder will turn to a very small fraction of a second and make it as difficult as possible to bump.

The lock will still probably give in to an electric pick relatively easily, but you will have made it as difficult as possible without actually getting a bump-proof lock specifically.

There is at least one treatment being sold that claims to make locks bump proof, but I have never used it, so cannot vouch for it personally.

For this reason most bump keys are cut lower than the lowest cut. I think the simplest solution for a cheap way to make a lock harder to bump would be either using different strength springs in various places, or possibly grinding the face of the plug to change the spacing significantly.

[Engineer]

As I said in my post, bump keys can be cut to "000" instead of "999" to take account of the greater depth needed by a pin of maximum depth - However, in my humble experience, bump keys are still being cut to "999". I would say most keys probably still are 999s, possibly because code cutters have problems cutting anything deeper.

People who file their own are probably making 000s. Cutting bump keys deeper than 999s is a relatively recent thing to become public, although professionals have knowm the 999s limitationsand how to get around it for a lot longer than it's been public.

Using a stronger spring in just one of two positions can help - If you can get them and if you put them in the right places.

You can perhaps salvage some springs from old locks, but if you put them above the 9-length pins, you will actually be making the lock easier to bump. You need to put the strong springs above the shortest pins. The reason is the inpulse will need to be weak enough to barely lift the "9" pin(s), but also strong enough to lift the "1" pin(s) all the way to the top. If the spring above the "1" is actually stronger than the pothers, then it makes it even harder to lift that pin high enough with the impuse from the bump, without lifting the "9" pin(s) too far.

As for grinding the face of the plug, perhaps I'm not understanding what you mean properly? From what I'm visualising, that would just make the key stick out further from the lock. It wouldn't change the spacings between the pins at all and would make the lock weaker and more vulnerable to destructive entry methods?

[yono]

As of now, i havent know of any lock manufacterer that proved their locks are truely bumproof. however most of us locksmith are also finding a practical solution to it. I had been expirimenting also as what MCM151201 been suggesting. Installing Compression springs of different strenght randomly on a six pins tumbler lock cylinder, with an additional modification on three bottom pins (making a narrow slot near the top end.) this two feature, is quite significant on my observation as i bumpkey the cylinder. the modified bottom pins mostly "hanged locked" between the shearline, and the two medium strenght spring have some delay when "kicked" by the bottom pin when bumped. this is quite significant for me, as it shows good resistance to bumping. And i havent been able to turn this cylinder up to this submission. maybe i need some more practice. but the more it take my time the more i will be satisfied.

[Engineer]

I don't think you ever can prove your locks are bump-proof, as someday someone might find a way round it. All you can say as a locksmith is that some locks are generally considered more bump-proof than others.

Putting your own grooves around the tops of the lower pins seems a good idea. Not sure how well it would work on a master-keyed system though of course, but the OPs original point was about how to try and make his existing lock as bump-proof as possible. I'm assuming he doesn't have different re-pinning kits (?), so might have to salvage some springs if possible to get the different compression rates (strengths) of them and that his lock is not master-keyed either (?).

One idea that "might" show an attempt at bumping, might be to make the second pin of glass rod. Borosilicate glass grinds fairly nicely, so if you could find glass rod of the right diameter, you might be able to make your own? (scientific lab glassware suppliers might stock rod of the dia. perhaps, or just have to do a seach for it). It would rely on the impact of a bump being a lot more than just inserting the key. It might work, or it might not. It would only be an experiment really, with no guarantees sadly.

Good luck with whatever you try

[Engineer]

My apologies to all, I knew the glass pins idea was on here, but I could not find the thread - Just found it now:

http://www.lockpicking101.com/viewtopic.php?f=25&t=43609

[fireware]

Using an obscure or controlled keyway would stop casual bumpers, I would assume. I've use Primus at work, and unless you can trick the locksmith to sell you a blank for the sidebar, then you won't be able to bump the lock.

[globallockytoo]

Using an obscure or controlled keyway would stop casual bumpers, I would assume. I've use Primus at work, and unless you can trick the locksmith to sell you a blank for the sidebar, then you won't be able to bump the lock.

This is not true! Anybody that has access to any key of any system, with the correct sidebar combination, can modify that key into a bump key.

Any system that uses two sets of pins, bottom and top, can have it's key modified into a bump key.

The fallacy that you need access to a keyblank is fundamentally flawed.

[globallockytoo]

As of now, i havent know of any lock manufacterer that proved their locks are truely bumproof. however most of us locksmith are also finding a practical solution to it. I had been expirimenting also as what MCM151201 been suggesting. Installing Compression springs of different strenght randomly on a six pins tumbler lock cylinder, with an additional modification on three bottom pins (making a narrow slot near the top end.) this two feature, is quite significant on my observation as i bumpkey the cylinder. the modified bottom pins mostly "hanged locked" between the shearline, and the two medium strenght spring have some delay when "kicked" by the bottom pin when bumped. this is quite significant for me, as it shows good resistance to bumping. And i havent been able to turn this cylinder up to this submission. maybe i need some more practice. but the more it take my time the more i will be satisfied.

Guess you havent seen Abloy or Bilock? The first 2 100% guaranteed bump proof lock types.

[globallockytoo]

BTW.....in Saudi Arabia you can purchase Bilock from

UNIVERSAL BUILDING MATERIALS MERCHANTS LTD (UBM)
P.O. BOX 9313
RIYADH 11413
Phone: + 966 1 4607553
Fax: + 966 1 4608231

(found on the www.bilock.net site)

[yono]

I just had finish my project regarding this bumpkeying thing, a new concept i think. i am preparing to illustrate it in black and white. i will post it tomorrow . i hope it worth it.