bump (key) for (no) justice

December 7, 2008 9:17 PM

It looks like someone tried to open my front door with a bump key. What should I do?

The deadbolt lock on my front door has become very difficult to open, and there is the imprint of the top of another key on the front of the keyway. I'm a little freaked out. Should I report this to the police? Is it likely whoever did this will be back later?

Any suggestions as to what I might do?

posted by oats to home & garden (13 comments total)

Change your locks? ISTR that a number of newer locksets are bump-proof.
posted by jacobian at 9:30 PM on December 7, 2008

I've been trying to educate myself as to what locksets are bump-proof.l Will probably be buying a new one in the next 12 hours or so...
posted by oats at 9:48 PM on December 7, 2008

Call up and report it, it'll help them if it's part of a pattern of burglaries and it'll help you if it happens again because they'll take you more seriously.

btw, there are 24 hour locksmiths who will come and change your locks right now. If you can't find one in the yellow pages, the police will be able to put you in touch with one.
posted by fshgrl at 10:19 PM on December 7, 2008

My boyfriend did some research on bump-proof locks when we moved into our new place. He recommends BiLock or Medeco.
posted by scody at 11:10 PM on December 7, 2008

A good locksmith will advise you on the bump-proof thing.
posted by mandal at 12:44 AM on December 8, 2008

What's bumping/bump-proofing?
posted by taff at 1:20 AM on December 8, 2008

What's bumping/bump-proofing?

Bumping , bump proof locks.
posted by The Light Fantastic at 2:13 AM on December 8, 2008 [1 favorite]

If I recall correctly, the more expensive locks (Medeco, Assa Twin) are actually easier to bumb because the mechanics that make locks harder to pick (pins lining up more evenly, making tension-picking harder) make bumbing easier.

Check out lockpicking101.com as they have a very active forum and are rather friendly; The question of un-bumpable locks has shown up there on many occasions.
posted by monocultured at 5:46 AM on December 8, 2008 [1 favorite]

Taff, it's a method of taking a blank key that fits the keyway of a particular lock, and "bumping" it with a small hammer/mallet. It makes all of the pins of the lock jump up, and if you try to turn the blank key at the same time the pins are falling back down, they'll catch in their respective "right" spots and the lock will open. It's sort of like lock picking, but faster and generally more effective.
posted by craven_morhead at 6:49 AM on December 8, 2008 [2 favorites]

Thanks all who answered. After reading some of the sites mentioned, I realize that my door frame is not all that secure--it has a flimsy post and a sidelight on the lock side. So I'm not going to try to go too crazy with the new lock. And I will file a police report. Thanks again.
posted by oats at 8:03 AM on December 8, 2008

@craven.

You don't use a blank for a bump key, but rather a key that is all filed down to 9 (IIRC) which is the "deepest" notch used in any given lock. If you're using a blank you would push some pins (if not all) above the sheer line, blocking the cylinder.

You use blanks when doing impressioning though, which is a step-by-step process whereby you try to figure out how "long" a pin is – i.e you're trying to reverse engineer the key.
posted by monocultured at 1:16 AM on December 9, 2008

Oh, right mono, I misspoke (typed); they're filed down and not blank.
posted by craven_morhead at 8:20 AM on December 9, 2008

Update: I went to buy a new lock from a locksmith I trust. He managed to convince me that my problem was unlikely to be someone messing with the lock, but rather much more likely to be moisture and corrosion. He advised me to put powdered graphite in the lock, and operate it a few times. I did this, and indeed it started operating quite well.

I decided against buying a new lock, and I haven't had any indication in the mean time that anyone is doing anything sinister. False alarm, I guess. Thanks to all who answered.

(one day I will have a question here that isn't a false alarm, I promise...)
posted by oats at 5:18 PM on January 7