Combination Lock

Does anyone know if there’s a way to figure the combination to a combination lock? I want to break into a box I locked up long ago, but I’ve forgotten the combination to the lock.

The lock is one of those standard stainless steel ones that has a black dial w white numbers. I think I remember 2 of the 3 numbers in the combination, but not the sequence in which to use them.

I really need to get into this box.

It sounds like it’s bolt-cutter time.

It would probably be far quicker to cut the lock off. I have successfully used a Dremel rotory tool with a cut-off wheel in the past to accomplish this. Alternatively, if the box is small enough, position it so that “U” part of the lock is securely resting against a hard stationary surface, and give it a good whack with a hammer a few time. This should shatter the brittle, yet hard U part and not damage the box.

Now, assuming you are really trying to open a box, and not some neighbors toolshed, you can try and listen to the tumblers falling inside the lock.
I’ve never done it, but supposodly when the correct number is reached, the lock makes a different noise. I imagine this is very hard, and would probably require a stethoscope or other noise-amplifying device, as I have tried to listen to a lock I did know the combination of to see how it was done, and didn’t notice any different sound.

Personally, I’d go for the bolt-cutter option myself.

Perhaps you might mention what the name of it is & who made it???

If it is a generic lock (not Master) you can probably remove it in 3 easy steps.

  1. Find a blunt intrument (shoes work well)
  2. Hit downward on the dial part of the lock as hard as you can.
  3. Repeat step 2 until lock is open.

In my gym class in high school this one done all the time*. Almost all of the non-master locks could be knocked open with one hit.
*Not to steal anything from the lockers, just to lock the lock on the water pipe near the ceiling. At the end of the semester there were about 6 locks still up there.

Why don’t you write to the manufacturer, giving it the serial number?

Works for any combo lock:

Pry dial off with a flathead screwdriver, takes awhile, but works in a pinch. Pull the steel rod out from the center with pliers, and lock opens.

If you remember two of the three numbers, then it shouldn’t take too long to simply go through all the permutations (I assume the dial has 60 numbers).

If the numbers you know are A and B, then the possibilities are A-B-60, A-60-B, B-A-60, B-60-A, 60-A-B, and 60-B-A, with the ‘60’ meaning sixty possibilites. Total of 360 permutations.

But, most locks are inaccurate and have a spread of about 2 or 3, e.g. when dialed to 10, it will work if the needed number is 9, 10, or 11. So, the total number of permutations may be closer to 120. Shouldn’t take too long (and will save the lock).

For Master locks at least, the combination is written on the underside of the dial, and prying the dial off isn’t too hard (you have to be gentle to avoid breaking it, though). You have to be very careful to get the dial back on in the correct orientation, though.

The advantage to doing it this way is that it doesn’t destroy the lock.

I recall when I was young my father was teaching industrial arts and the kids were given lockers.

Once he came home after a school year with about 50 locks that couldn’t be used as they had lost the combinations.

My brothers friend Eddie walked over and proceded to pick every lock. He said you just pull up on the U shaped piece while turning the dial and listen. The tumbler makes a noise as it hits the correct number.

I never was able to do this but he got every lock opened.

You can pick it, but it’s iffy- I can get some and not others.
Get in a quiet place, know the turn pattern (r-l-back one whole turn and then to last number, for example)
Quiet place sounds kinda wierd, because you aren’t going by sound, but by a ‘feel’- noise distracts from this though. It can take a while- the feel can be deceptive. I understand it’s not to guys who are good at this, but I’m a rank amatuer…
Still, with two numbers known, looking for a feel, which gets deeper the more right numbers/directions you have hit, you might have a good chance at it.
The other thing is to pull up, as Mark said. Again, this is tricky- try various pressures- too much and you can’t turn the dial or get a false feel. Too little, you get no feel or a false one. It should lean toward too little rather than too much though.

Even the master locks can be opened very easily with the “blunt object” method listed above. In high school and in the service, master locks were used exclusively. Best method for those was to get a piece of pipe or rod, put it on top of the lock, not on the dial, and hit it with a hammer.

If the box it’s attached to is portable, you may be able to take it to a locksmith’s shop and get the combo there. I’ve done this with bike locks (not with the bike attached, however).

TurboDog got it right. My workplace uses Master locks, and the universal combination is often called “one down.” Though whacking the dial will usually knock the dial off without opening the lock, bashing a bar placed atop the casing inside the shackle always works. Sometimes the lock even works afterwards.

a) hit the bastard with a hammer till it yeilds.
b) cut the bastard.(dremil or bolt cutters)
c) take it to a locksmith shop

Some combo padlocks have a code on the back that can be looked up by locksmiths to get them open. I have never worried or tried real hard to manipulate one of the little combo locks. Is not worth the time.
Now if it were a actual safe I HAVE done those from time to time. They are a whole different animal and very time consuming and well could write a book on that.

anyhow, cut or break it off and replace it for cheap.


I’ve seen shims for combo locks before, though I’ve never used one. As I recall, they’re thin strips of stiff metal, shaped something like those “breathe right” strips - narrow in the center, flaring at the ends. My understanding was that you slide one down the inside of the shank on the side that comes open. It forces the … doodad to disengage from the notch in the shank, et voila. I don’t know if one must be a registered locksmith to obtain them, however. Good luck.

I just ‘picked’ an old combination lock that we had lying around here and that I had forgotten the combination to. It looked like a master, but was some kind of knock-off. Anyway, All I did was put tension on the shank by pulling on it, then slowly turned the dial trying to feel when the cam caught inside. On this lock, the resistance in turning the knob would drop a bit when it hit the right number.

I played with it for about 10 minutes before I managed to get it open.

Do a web search, there are clubs and FAQ’s for this kind of stuff. I learned how to pick most Master locks. I pick up the “unclaimed” ones at the gym, and make them my own.

For many models, you can…
put tension on the shank to get the last number. It will stick more than the others. In fact, there should be tension at 6 points, of which 5 are equal in mod 5 or something (again look it up), the remaining one is the last digit.

The second digit remainder when divided by 4 will be 2 off the last number, and the 1st will be equal. (So if the last number is 28, the second one will be 2,6,10,14,18 etc and the first one will be 0,4,8,12,16 etc) That leaves you with 100 combinations to test. It shouldn’t take more than 20 minutes to go through them, especially as you only test 50 on average.

Again, look it up on the web. It’s out there.

Muttox and typo are right. While borwsing thru a trade magaine I reseached both the shim and manipulation process and depending on the type of lock work very well.
I personally still cut the bastards