Bump Key Diary

[whiteknight38]

I first heard about bumping in 1996 at an ALOA convention, and I dutifully did some experiments, but was unimpressed and ultimately abandoned the idea. It’s fair to say that I was someone who dismissed bumping as “a lot of nonsense.”
New developments in the practice: deep-cuts, minimal movement, and high-security bypass successes, have caused me to revisit and reinvestigate the practice, and, consequently, reconsider my position.

I recently ordered a set of keys and hammer from an online distributor and began keeping kind of “bumping diary.” I started to work my way through a couple of 5 lb. coffee cans full of cylinders, while keeping a window open at the bottom of my computer screen to record the results.

I closed my study at 52 because that figure conforms to the number of locks on a different “Diary” I kept some years ago on locks that I raked open in the field as a locksmith. (I posted the results of this study in a reply to “Bumping as a locksmith” thread.)

My bumping study is completely non-scientific, as I was pretty clearly making up the methodology as I went along.
Some locks were new, some were old.
Some locks that I failed to bump open were attempted with other tools, (rake picking and/or a pick gun) and some weren’t. (Any locks that I failed to open by “other means,” however, were binned, and not included in the final numbers.)
All locks were worked on in-doors, un-mounted, without regard to turning direction.
A handful (seven) were attempted with a homemade tension wrench I fashioned out of a bobby pin, (four of the seven were successful) because after the first couple of hours, my fingers were getting sore.

I think the bobby pin wrench idea, by the way, is worth studying further.

I started with a five minute benchmark for “Bump failure” but at lock #30, I reduced the maximum time to 2 minutes in line with the earlier raking study.

It must be noted that while I am an amateur at bumping, I have years of experience in lock picking.

The results of an initial sampling of 52 locks follows: 26 cylinders out of 52, (exactly ½ of the study sample,) yielded in less than five minutes. 23 out of the 26 that were successful yielded in under two minutes. 21 of the 26, in under 30 seconds, and 14 of these, in under 10 seconds.

I may repeat the test, after a few months, with tighter controls, and a stricter methodology, and see if the numbers improve with practice and experience.

I still don’t see bumping replacing mechanical or hand picking in the field, but I have to say that overall, I was both surprised and impressed with the success ratio. Especially, since the learning curve for bump key use is so short.

The fact that an individual with no experience, can walkup and successfully open nearly half the locks attempted, was pretty shocking.





BUMPING DIARY Feb 2007


Schlage (SC) generic mortise Used quite greasy actually twenty seconds
Kwikset (KWI) KIK generic Used Five seconds
SC KIK Used. 6 Pin Couple of minutes. Down to ten seconds with practice
Yale KIK five minutes gave up. FAIL
Everest Original New 6 pin five minutes FAIL
Weiser (WR) original KIK New one minute
WR generic KIK Used Ten seconds
SC original KIK New 6 pin five minutes FAIL
KWI mortise used five minutes
Weiser original KIK new five minutes FAIL
KWI generic dblt used five minutes FAIL
WR generic dblt used five minutes FAIL (Raked 5 seconds)
SC generic dblt NEW three minutes (With Paper clip wrench) PCW
SC generic dblt NEW ten seconds PCW FAIL
SC generic dblt NEW five minutes PCW
SC generic dblt NEW 30 seconds PCW
SC Original Dblt 5 min FAIL
SC generic dblt used thirty seconds PCW
SC generic dblt used five minutes PCW FAIL
WR generic dblt used ten seconds
WR generic dblt used ten seconds
WR generic dblt used five minutes PCW FAIL
SC original dblt used 5 minutes FAIL
SC generic mortise used 5 minutes FAIL
Yale KIK used 5 minutes Pick gun 5 One click Multiple repeats - FAIL
SC generic Mortise 5 minutes Pick gun - five seconds Multiple repeats FAIL
WR generic Rim Used Very weak springs? No bounce back effect FAIL
WR kik generic Used Weak springs – “pull out” necessary 5 seconds, repeated
WR KIK generic Used five minutes – Pick gun under five seconds, repeated FAIL
SC mortise original, Used (Unknown keyway) 3 minutes – repeated in 5 seconds twice
WR dblt generic New 2 minutes gun 5 seconds FAIL
WR dblt generic New 2 minutes Pick gun 40 seconds FAIL
WR dblt generic (DEFIANT)Used 2 minutes Pick gun 11 seconds FAIL
KWI dblt generic Used eleven seconds
WR dblt generic (EZSET) Used 2 minutes Pick gun 3 seconds FAIL
37 WR generic dblt New 70 seconds
WR KIK generic New 2 minutes PICK GUN FAILED for two minutes Rake15 seconds FAIL
SC KIK generic New 15 seconds
WR dblt generic New 2 minutes Pick gun 2 seconds Rake 16 seconds FAIL
WR dblt generic New Just -2minutes Consistently under 10 seconds hard bumps
WR dblt generic New Under 10 seconds (Double-cylinder brother of above lock)
SC dblt Original Used Just under 2 minutes Harder bumps 10 seconds
SC dblt Original Used Just 10 seconds
SC KIK generic Used Just 40 seconds
WR dblt Generic New 2 minutes Pick gun 4 seconds FAIL
WR dblt Generic New 2 minutes Pick gun 2 seconds FAIL
WR dblt Generic New 20 seconds
SC dblt Generic New 6 pin 10 seconds
WR KIK Generic New Pick gun 5 seconds FAIL
SC dblt Generic New 6-pin 25 seconds
WR dblt Generic (EZSET) Used (Greasy feel) 2 minutes + Pick gun 10 seconds FAIL
KWI dblt Generic (LSDA) Used 5 seconds

[linty]

that's really interesting, it's nice to see an objective look at bumping success, i thought maybe i was the only one who had complete failures about half the time.

[CVScam]

I was looking at your results and I had a few questions do you only have one bump key for each keyway? I have a set of bump keys a locksmith friend made for me and I have keys I have hand filed. I have a lot better luck with my hand filed kw1 keys than the locksmith made kw1 bump key. I was also wondering if you tried different tools to do the bumping with, for example I have to use a heavier tool to bump my Schlage locks. The final question I have is how much luck have you had bumping padlocks?

[le.nutzman]

I think with bumping, the success ration is based on two factors. First i believe that how the lock is pinned has alot to do with your success. If the lock has deep cuts towards the back of the lock, or anywhere in the lock, this has a tendency to hinder the bumping process. Hinder, not stop.

Second, I think that how you bump the lock has a great deal to do with your success. The pull out method vs. minimal movement. An example of this would be last pin deep cut. Pull out methodology would show that the last pin when bumped rises completely to clear the initial key peak therefore causing both top and bottom pins to remain closer together longer during the bumping process. Effectively hindering the lock's ability to be bumped open. While the minimal movement works more off shock and energy transfer, the same pin is struck, moves slightly to transfer its energy and settles sooner, the time that this pin and it's associated top pin are separated is longer, therefore the shearline is exposed for just a fraction of a second longer and the lock is now able to be bumped.

I have conducted this test on several Amercian Series 5200 padlocks that I have and have even gone as far as repinning them as previously suggested to test the theory. As such, i have found several locks that I can't bump open using the pull out method within any amount of time that would be considered reasonable or benenficial. However, those same locks I can bump open time and time again using the minimal movement technique in a matter of seconds.

I've used bumping to open several locks here when conventional means have failed or time was a factor and the bolt cutters weren't in reach. I see it as a plausible use. Like any other field, sometimes you just gotta do whatever works as long as the end result is the same, lock's open/objective met.

[whiteknight38]

Don’t get me wrong, I’m not the anti-bumping guy I was a couple of weeks ago. I might try bump keys with my new professional looking bump hammer, for a couple of minutes if all else failed. I just wouldn’t reach for it first, since I get more consistently reliable results from my Lockaid gun, and my picks.
A couple of points were raised bu CVScam and le.nutzman that I’d like to address. I did no tests on padlocks. No, I don’t have more than one key per keyway, although I can see the advantages of having a sub set of non-shoulder/tip reduced keys for the pull-out method.
Certainly it’s a truism that some locks, for whatever reasons, are more consistently vulnerable to one approach or another, over any and all techniques attempted. One lock in the bump survey refused to bump at all, but gunned repeatedly, over and over, in less than five seconds.
Other locks bumped virtually instantly, especially once I got the specific turning tension, and rapping pressure appropriate for that lock down pat, but were less susceptible to gunning, relatively speaking.
Other locks in my experience, rake open so easily, it’s simply a matter of inserting the tools to get them to turn. In one case I can think of, it was absolutely a pinning issue, as an inspection of the key revealed five cuts as regular and even as the teeth on a saw blade.
Tension and hammer intensity are also obviously factors, and one person will be successful on some locks where another fails, and vice versa.
I can think of one padlock on the canteen locker at work, (where we keep coffee, sugar, and etc) that I just can’t seem to get, but a colleague has no trouble with at all. I defer to him, when the locker key goes AWOL.
This guy ruins wrenches regularly, however, and it seems likely that the secret is to put tension-wrench warping pressure on the thing to get it to open, something that I just can’t bear to do.

[BobbO45]

On the subject of bumping pad locks: I have filed two masterlock m1 keys myself - one for the minimal movement and one for the pull-out method. I was surprised at how many different key ways that these keys will fit into. I have tested on several locks:

Two No. 3 Master locks (4 pin)
a Ronko lock (4 pin-looks like the Master No.3)
an ACE lock (5 pin with spool pins-Brass)
a ?Brinks? lock (5 pin-Brass)
another Master, maybe No. 3 - it came covered in speckled paint so I cannot read any stampings.

Results:

After lube the two No. 3 Master locks will bump either first or second time nearly every time.
The Ronko will usually bump within the first 4 or five attempts.
The ACE lock, surprisingly bumps very easily - usually the first time, even though the m1 key I am using is only 4 pin, with a 5 pin lock that has spool pins.
I have been unsuccessful so far with the ?Brinks? brass padlock, although I notice that the minimal movement key goes in and rests with no gap between the shoulder of the key and the plug. The pull out key goes in, but rests with two large of a gap between the shoulder and plug. I think that the lock will easily bump with the correct key filed down, but so far it will not work with the m1 key.
The third Master lock uses an m1 key, but so far I have been unsuccessful in bumping it with either of my homemade keys.

In all of the above cases I have found, like others, that the minimal movement key works much better (not to mention it is faster-no reset after each hit). Also, for a hammer I am using a homemade one that has some flex, and found it to work incredibly well in comparison to all other things I have tried. I have come to the conclusion that the hammer one uses is critical.