Easiest way of altering a standard lock to prevent bump keys

[grndslm]

Long story, short.... I'm curious whether or not serrated or spool pins would be more effective at stopping bump keys from bypassing my deadbolt.

If you can't replace top, driver pins from each individual chamber easily, then I'd think using two plug followers to just change the outside driver pins would be the EASIEST thing to do, no?

Gordon's idea is to, at minimum, use a heavy duty spring at the last pin (where the tip of the key would be, to prevent excessive wear on the key). Where to buy a few of these springs?

Also, which "security" driver pins should be used to replace the regular old top pins? Serrated pin in the first chamber, t-pin at the last (with the heavy duty spring)??

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Continuing this thought from here...

by GWiens2001 » Sun Dec 06, 2015 11:19 am

Sometimes serrated is better than spools against picking, especially if you thread the pin channels.

Neither have much effect on bumping. For that, you can get Schlage T-pins, which also come with strong springs. They help. Varying spring tensions (strengths) also help, since the rebound rate is different, throwing off the timing when bumping.

Not an expert at bumping, as I prefer not to do things that so easily damage the lock. But when I set up a lock for friends who are concerned with bumping, I put in a couple T-pins, and have at least one cut of the key be the deepest cut possible. Then put a very weak spring on that pin stack. This makes it so if someone is bumping, it is very easy to overset that pin stack. Also, I make the pin stack at the tip of the key very shallow (short key pin) and have an extra strong spring there. That means you have to really whack the key to get that pin to go high enough to set that pin, pretty much assuring that the deep cut pin has to be over-set.

If you do use an extra heavy duty spring, only put it in the pin stack at the tip of the key to reduce key wear on all the pin stacks.

And, of course, if you get a disc detainer lock such as an Abloy, or a driverless lock like a BiLock, then you have no concerns with bumping.

Just a few ideas you may consider. Members who do a lot of bumping may have better input, or may think my ideas don't work. If so, hopefully they will speak up, as bumping is not my forte.

Gordon

[grndslm]

Hmm.... I can't edit here....

Just wanted to add....

Perhaps various length top pins could create an effect that is similar to adding heavy duty springs. Instead of a heavy duty spring, just put a long driver pin in that last chamber?? That's probably not as good, but a decent solution, maybe? Long spool pin in the first chamber, and long serrated driver pin in the last chamber?

Longer pins would be compressing the spring more, building up more potential energy... I believe... but this could just weaken a stock spring to its original "compression rate", or whatever that term is I'm looking for.

[Squelchtone]

Your best bet is to get a keyway that is not common to most bump key sets available for sale on the internet. stay away from using Kwikset KW1, Schlage SC1, Yale Y1, and Arrow AR1. Get a 6 pin Schlage or an Medeco Air keyway if your door hardware allow for a mortise cylinder. If limited to a regular North American tubular deadbolt, get a 6 pin Schlage or something more restricted like an MX cylinder. changing pins and springs out may or may not work to stop someone with bump keys.

[grndslm]

This seems like solid logic to me...

viewtopic.php?f=8&t=43559

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".

.......

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.

Also ran across the Ilco "Bump Resistant" Conversion Kit, which appears to just be a super long T-pin with a [more than likely?] heavy duty spring... http://www.clksupplies.com/shop/ilco-bu ... -2056.html

Here's a video... https://www.youtube.com/watch?v=EzIJlNYPuso

I think I'm just gonna re-build all my locks myself.... Get a basic Schlage kit (mostly for the plug follower and plain bottom pins) from ebay, this Ilco kit, and then both some serrated and spool top pins. Wish I could just find one site that had serrated and spool bottom pins, as well as the hybrid serrated/spool pins, both top and bottom. That would be the jackpot. Just a bunch of different lengths of the hybrids would be awesome.

[grndslm]

Getting closer!!

LAB's High Security Pin Kit for $55 .... http://www.lockpicks.com/high-security-pin-kit.html

-or-

CLK's High Security Pin Kit for $32 .... http://www.clksupplies.com/shop/high-se ... -2697.html

I think I'll take the latter. It appears that there isn't a decent source of bottom security pins, much less a kit. However... if you were handy with a precision engraver w/ dremel attachments, you could probably fashion your own bottom pins with LAB's kit. Hmmm.....

Still can't find a source for the hybrid pins.

[cledry]

Getting closer!!

LAB's High Security Pin Kit for $55 .... http://www.lockpicks.com/high-security-pin-kit.html

-or-

CLK's High Security Pin Kit for $32 .... http://www.clksupplies.com/shop/high-se ... -2697.html

I think I'll take the latter. It appears that there isn't a decent source of bottom security pins, much less a kit. However... if you were handy with a precision engraver w/ dremel attachments, you could probably fashion your own bottom pins with LAB's kit. Hmmm.....

Still can't find a source for the hybrid pins.

Don't follow the instructions on CLK's site though. Never put spools in all the chambers.

[MBI]

Never put spools in all the chambers.

Even though they say to never put spools in all chambers, back before I upgraded to high security locks, that's what I did. I wouldn't recommend it for most lock owners as it makes key insertion a bit rough since you don't have standard pins in at least one of the pin chambers to hold it lined up straight. I found it can make bumping a bit tricky because of that same feature. I think it's because if the lock is turned even a tiniest little bit while bumping it, when the key is smacked some of the spool pins will catch on the way up and fail to bump up over the shearline.

It's bump and pick resistance I'd do for myself since I know what to expect when inserting the key, but I wouldn't do it for a customer.

[nite0wl]

So including spool driver pins might help a little. Adding one or two T-pins with new stronger springs (stronger than those in the other chambers) helps a lot more. As a couple people noted, the less common your keyway, the harder it is for someone to get a bump key for your lock in the first place.
Ilco makes a kit for retrofitting locks that use standard pin sizes that only require swapping springs and drivers. Serrated pins do next to nothing to prevent bumping since bumping is all about bouncing the pins and catching them at the shearline, interfering with that means altering the mass of the pins and the resistance of the springs from chamber to chamber so that each chamber will react differently.

[MBI]

So including spool driver pins might help a little. Adding one or two T-pins with new stronger springs (stronger than those in the other chambers) helps a lot more.

If you try the spool pin trick, they ALL have to be spool pins. Won't work if only some are spools. If even one top pin is a regular pin, it won't have the same effect because that one pin will keep the plug and pin chambers aligned. When they're all spools, when the pins are at rest (as when there is no key or there is only a bump key inserted) it's possible to rotate the keyway a tiny bit. Even then, it's no guarantee against bumping. It just means it's less likely to work because if they apply any tension at all to the key or if it's turned even a tiny bit before they whack the key, then the spools will catch so it won't bump. If they happen to get it all lined up straight, it's still bumpable.

[Jacob Morgan]

http://www.clksupplies.com/shop/ilco-bu ... -2055.html
http://www.clksupplies.com/shop/ilco-bu ... -2056.html

Either of these kits cost $9.90 and can retro-fit 10 locks, so for $1 a lock one can make it much harder to bump so long as one knows how to change out top pins. The kit goes over what position(s) the pins can go in and what bottom pin heights it works best with.

It uses an upside-down T-shaped top pin with a very heavy spring. Added one to the SC1 keyway on my front door last week and I can't tell the difference in using a key. Given the light pin and the heavy spring it would really mess up the physics of bumping. The T shape would give most pickers a fit as well. I may add a spool or serrated pin to the lock as well to further discourage picking, but I'm much more concerned about bumping than picking.