opening a metal cabinet with a safe-style lock

Can one open a combination lock without knowing the combination?
I'm helping to clear out a building which is about to be torn down, and in the office is a sheet metal cabinet, with a door on the left side and two shelves inside, and on the right side is a larger door with a safe-style lock on it, a single dial, a black plastic wheel with numbers on it.
By no means is this worth the money that a professional would charge -- we never even locked it when we were using the building, or we would still remmeber the combination -- but it seems like a challenging project to me.
It got locked somehow and no one remembers the combination. I've heard that it is still possible to open them. That the movies are not entirely wrong, with someone using a stethoscope to hear the "tumblers" "fall" into place.
OTOH, I had a toy safe, when I was about 20 years old, twenty!, and it was clear plastic inside, and I could see the gears turn when I turned the dial on the front, and even in this toy, there were no tumblers to fall as one or more of the three wheels (the gears) each with a notch in one place, got their notches lined up. Only when all three notches were lined up, could one open the plastic safe.
There was nothing to hear until the last second when it opened. Rotating the knob and the gears made no special noise at any point (except maybe a noise could be heard after one reversed direction of the knob and when a cog on a gear close to the front hit a stop on the next gear back and it started to turn. but what has the number that is at the top of the dial at that moment got to do with the combination number? Is that it? Can the latter be deduced from the former?) I don't see how it could be.
From Wikipedia "Some rotary combination locks can be manipulated by feel or sound in order to determine the combination required to open the safe. More sophisticated locks use wheels made from lightweight and soft materials such as nylon, which reduces this vulnerability." This seems like nonsense. Why does it have to be "sophisticated" when my 4 dollar plastic toy safe couldn't be opened by feel or sound?
One webpage says "Despite the tried-and-true design of the safe, it contains a fundamental weakness: Every safe must be accessible to a locksmith or other authority in the event of a malfunction or lock-out. This weakness forms the basis of safecracking." It says "every" but does that really apply to something that probably costs no more than one or two hundred dollars new now.
BTW I don't think this is a fire safe or a real burglary safe. It bangs too much to have fire insulation in it (and I saw it when it was unlocked and open, come to think of it) and anyone could cut into it with a hack saw, or a boy scout can opener, or puncture a hole with a big screwdriver.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Yes. I've seen a floor safe opened (with permission from owner). One pool cue rested against the ear gently (cue tip to dial area) as the other persons turned the dial, try a wooden dial or long screw driver.
Many years ago, though!
-- Oren
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Well, I guess I will try it. I have an engine stethoscope that ought to work well
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I somehow sent this before adding
http://home.howstuffworks.com/safecracking1.htm This page has an animated version of how tumplers work. (BTW, I was a tumpler in high school so I think I know apout them. ;-) )
http://home.howstuffworks.com/safecracking4.htm
I think this is the page that talks about hearing clicking at the start and end of the contact area. In my toy plastic lock there was no contact area. The bar rested on the last wheel and did not move up or down until all the notches were lined up. But I'm going to try his method anyhow.

Well, I guess I will try it. I have an engine stethoscope that ought to work well
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I doubt there are any "tumplers" in any safe that fall. I figured out the combo for a fairly expensive (open) Mosler safe and it was a pretty simple mechanism, similar to your toy safe or a Master combo padlock. Disks with slots and a pawl that was pushed into all of them at once when they were lined up and you turned the handle
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Call Geraldo and he'll do a 30 minute show on it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

ROTFLOL. He probably would.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
mm wrote:

I saw a device designed by an engineering student used to open a combination padlock. Its major parts were a small logic board, a servo, and a solenoid. After attaching the servo to the dial - and a little alignment - the sucker diligently went through every possible combination!
Always worked.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Site Timeline

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.