How To Crack A Safe With Pictures

The spindle and other parts are not visible even with the safe door open.

A small drive pin extending from the drive cam serves to catch against the wheels (see below) and set them rotating.

A combination lock has one wheel for each number in its combination (typically 2–6). For instance, a lock with a 3-number combination (e. g. 25-7-14) has three wheels. Knowing how many wheels there are is important for cracking the safe, but there are ways to discover this number without knowing the combination (see later parts). Small tabs on the wheel called the wheel fly catch against the drive pin or next wheel and sets them rotating. This term is not important to remember for this guide; just know that the drive cam makes contact with the wheels to set them spinning.

Older texts may refer to this as lock drop, drop-pawl, or dog[4] X Research source (an obsolete term for any object that holds or blocks another).

You can see why there is one wheel for each combination number. When you dial the first number, the first wheel is rotated to a position with its notch directly below the fence. You then reverse the direction of your rotation to disengage with that wheel and turn the next to its correct position. The drive cam also has a notch for different reasons. The intended purpose is not important to know for this guide, but remember that this notch will “click” every time it slips past the lever (stationary part attached to the fence). (Extra information for the curious: once the fence falls and releases the locking mechanism, the drive cam notch catches onto the bolt physically blocking the door and pulls it out of the way. )[5] X Research source

The mechanism you’re listening to is located directly behind the dial, but obviously you cannot cover up the dial since you’ll need to turn it. Try moving the stethoscope between different spots adjacent to the dial as you spin the combination until you find the most audible location. Metal safes reverberate the sounds and make them easier to hear. These are a good choice for a beginning hobbyist.

One click will be fainter than the other, since the notch making the sound is sloped toward one side. You’re listening for the sound the drive cam notch makes when it slides under the lever arm[6] X Research source (see Learn How a Combination Lock Functions). Each side of the notch “clicks” as the lever passes by. The drive cam’s contact area is the name of the area on the dial face between these two clicks.

Clicks can be faint or obscured by other sounds. Repeat the process two or three times and confirming the pattern of two nearby clicks in a consistent small region of the dial face.

This is referred to as parking the wheels. You’ve placed the wheels in this location and can now count them as you “pick them up” by turning the dial.

Remember to listen when you pass the “parked” position, 180º from the original “contact area” you found earlier. The first time you pass that position, you should hear a click as a wheel is engaged and begins to spin with the drive cam. Each subsequent time, you will hear a click only if there’s an additional wheel to be “picked up”.

If you hear many clicks or clicks in the wrong position, you may have made a mistake while “parking”. Try again from the beginning of this section and make sure you are resetting the dial completely by giving it an extra few rotations. If you are still encountering the same problem, the safe you’re using could have anti-cracking technology. You may need to call a professional locksmith.

Each wheel corresponds with one number in the combination, so you now know how many numbers you need to enter.

Label one graph’s x-axis “starting position” and its y-axis “left contact point”. Label the second graph’s x-axis “starting position” and its y-axis “right contact point”.

Similarly, on your “right contact point” graph, mark a point at x=0 and a y value where you heard the second click. You can now label your y-axes. Leave enough room to graph a spread of 5 numbers on either side of the y-value you just recorded.

This new number is the next x-value you’ll record.

When you’ve recorded the second location, reset the lock again and set it an additional 3 numbers counterclockwise.

This is easier to see if you lay the two graphs one above the other and literally find the points where the two graphs are closest together. Each of these points corresponds with a correct number in the combination. You should know how many numbers there are in the combination, either because you’ve used this safe previously or because you followed the instructions for Find the Combination Length. If the quantity of converging points on the graph doesn’t match the quantity of numbers in the combination, make a new graph and see which points are consistently narrow.

If you successfully followed these steps, these numbers should be the ones used in the combination, or at least close enough to work. Note that we do not know which sequence of these numbers is the correct one. Read on for additional testing and tips.

Remember to attempt to pull open the safe door after each complete combination! You don’t want to be absent-minded and move on to the next combination before checking for success. Remember to reset the dial between each attempt by spinning it several times. If your dial has more than 2 or 3 wheels, you’ll probably want to write down each combination in advance and cross them out as you go.

For example, if the digits you wrote down are 3, 42, and 66, you’ll need to try every combination of [2, 3, or 4] + [41, 42, or 43] + [65, 66, or 67]. Don’t get confused and start testing combinations like (41, 42, 65); each combination should contain exactly one number from each bracketed trio. This is really only practical for a 3 digit combination or less (requiring a maximum of 162 attempts). For a 4-digit combination, the number balloons to a maximum of 1,944 attempts. This is still much faster than trying every possible combination, but will waste a lot of time if it turns out you made an error in your cracking attempt.

Keep your old graph and notes handy. If your new attempt gives the same partial results (for instance, 2 of the 3 numbers are the same ones you tested before), it’s much more likely those results are accurate.