Generally, it’s a good idea to keep personal items like social security cards that have little value to a burglar in a safe at home, but not valuable items like cash or precious metals. Most security experts will advise you to keep items like that in a security box at a bank. That’s because a safe is going to probably be one of the first things a burglar is going to look for when breaking into a house.

Most of the time, someone who burglars a home is not a master thief and generally doesn’t how to crack a safe, but that’s not to say they won’t just pick it up and carry it off. But if you do decide that you need to keep precious items in a safe at home, then you’ll probably want a really heavy safe that’s bolted down to concrete. Most of the time that’s enough to prevent someone from stealing from you, but every now and then, a safe gets cracked open by a professional burglar. So how does a burglar open a safe and how hard is it?

What Method to Use

Physically breaking into most safes would be extremely difficult so we’re going to assume that the burglar is breaking into it by learning the combination and manipulating the dial. For safes, the dial generally starts at 0 and counts all the way up to 100 with tick marks for each number. If you’ve ever seen a movie where they use a stethoscope to listen to clicks inside the safe to figure out the combination then you know at least a little bit about how it’s done.

What they don’t tell you is that it’s virtually impossible to accomplish if you don’t know how the inner parts of the safe fit together for the specific safe you’re trying to crack. For this you’ll need to know the model of the safe and acquire the blueprints so you can study the parts.

Understanding the Parts Inside a Safe

Attached to the dial there’s a rod that extends out and rotates with the dial. The spindle rotates the drive cam at the other end opposite the dial.  Extruding the drive cam is a drive pin which serves to catch against the wheels to rotate them in the correct position. These wheels (also called tumblers) are circular objects that don’t rotate with the dial. Instead they have tabs on them that will catch on the drive pin and rotate with it until the dial is turned the opposite direction. Generally, a safe will have one tumbler for each number in a combination. For example if you’re combination is 12-56-17 it’s probably safe to assume that the safe has 3 tumblers.

Finding the Combination Length

Finally the use of the stethoscope comes into play. Basically, you’ll be moving it around the safe listening for clicks while you turn the dial, but it’s a little more complicated than that.

1. Find a Good Listening Spot

The spot on the safe that you’ll be listening for clicks is located directly behind the dial. Since you can’t actually place the stethoscope on the dial it’s probably a good idea to move the stethoscope around while you turn the dial and look for the spot where you can hear the clicks most clearly. Metal safes have a tendency to amplify sound so if you’re a planning on starting this as a hobby you’ll probably want to start with a metal one.

2. Reset the Dial

Before you start listening for the locations of the clicks you should turn the dial clockwise for several full rotations. This will reset the lock and make sure that all of the tumblers are disengaged.

3. Rotate Counterclockwise

Now that you have the best listening position figured out, rotate the dial slowly counterclockwise and listen for two clicks right after each other. Be ready to take note of where the dial is located when you hear the clicks. One of the clicks will be a littler fainter than the other one because the mechanism will be at a slight slope. What you’re actually listening for is the sound the drive cam makes when it slides into the lever arm. Each side of the notch makes a sound as the arm passes it. Write down the dial location of the clicks.

4. Reset & Repeat

Now you’ll want to reset the dial again (step two) and repeat step 3 a few times to make sure you got the location right. You’re looking for a consistent location on the dial where you always hear two clicks. Remember to rotate slowly counterclockwise when listening for the clicks.

5. Find the Starting point

Once you’re sure of the location of the two clicks, move the dial exactly opposite of that click (180 degrees). This is commonly referred to as “parking the wheels.” Now that the dial is in this spot you can begin to count the clicks as you pick up each tumbler.

6. Count the Number of Wheels

Turn the dial slowly clockwise and pay close attention to the spot where you parked the wheel. Each time you hear a click from the parked position you’re hearing the drive cam engaging with an additional wheel. Each time you pass, you should only hear a click if there is an additional wheel. If you hear clicking from other locations or no clicking from the parked position then you may have made a mistake and need to restart. Now write down the total number of times you heard clicks from the parked position. This is the number of wheels your safe has and should tell you how many numbers are in your combination.

Getting the Numbers

Now we’re going to attempt to get the combination. This will take a bit of time and require gathering quite a bit of information.

1 Create a Graph

Grab some graph paper or create your own and make two graphs labeling the x-axis from zero to the highest number the dial reaches and on the x-axis (vertical) and on the y-axis just make sure there is enough space for 10 numbers or so (leave blank for now). Label one graph left and the other one right. One of these graphs will be the first click and the other the second click. Make sure the graph is spaced enough apart so that you can clearly see 3 numbers apart or closer if possible.

2. Reset the Lock & Set to Zero

Spin the dial several times clockwise to disengage all of the wheels and then set the dial to the zero position.

3. Rotate & Mark each point

From zero, rotate the dial counterclockwise and listen carefully. You’re listening for the clicks that indicate where the drive cam connects to the wheel. Once you hear the two clicks close together, these are the two points on the dial you’re going to want to mark down. On the left graph, make a mark on the zero position (where you started from) on the x-axis and in the middle of the y-axis (leaving room for 5 numbers left and right) mark the position on the dial you heard the first click. On the right graph do the same thing, but mark where you heard the second click on the y-axis.

4. Turn 3 & Repeat

Reset the lock and this time stop 3 numbers to the left of zero. This will be the next spot you will mark on the x-axis of the two graphs. Keep going until you’ve reached the end of the number of dials Skipping 3 to the left each time.

5. Analyze Results

On the two graphs there should be points where the y-axis values converge or are a lot closer together. Find the points where the y-axis results on the right and left graphs are closest. The easiest way to do this is to set the graphs on top of one another and look to see where they are closest. The amount of converging points should correlate with the amount of numbers in the combination.

6. Test Results

Now you will want to test these numbers by try each combination to see if the safe unlocks. Once you have tried each combination of these numbers, if you still haven’t been able to unlock the safe, start adding 1, 2, or 3 to each number. For example, if your numbers are 4, 56, and 12 then you would try these combinations:

  • (4 +1) (56 +1) (12 +1)
  • (4 +2) (56 +2) (12 +2)
  • (4 +3) (56 +3) (12 +3)
  • (4 +1) (56 +2) (12 +2)
  • (4 +1) (56 +3) (12 +3)
  • (4 +1) (56 +2) (12 +3)

And so on…

If you it still won’t open, try again from the beginning. Cracking a safe takes a lot of patience and there are a lot of things that could go wrong. If you’re worried about someone stealing from your safe, you should consider getting a home security system. Save money and have your home professionally monitored by getting a quote through Protect America today.