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How to Open an Attache Case Lock With a Lost Combination

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Attache cases with combination locks are usually a hassle-free way to keep your business papers in good condition during transportation, while ensuring the papers and any other valuable contents are safely secured. Three-digit combination locks are normally used on attache cases, so they shouldn't be too difficult to remember. However, with the number of passwords and security information we have to retain mentally, due to the rise in use of electronic media, it is not surprising that occasionally we do forget this kind of thing. If you have forgotten your combination, there are a few methods you can use to open your case.

Think back to when you set the combination. Try to remember what criteria you used to come up with the three-digit number. Maybe it was birthdays, house numbers or lucky lottery numbers, for example. If you can remember part of the number, this will help you confirm or eliminate any ideas you have about what it might have been.

If you still can't remember the code number, crack the combination using a business card, or something similar. This will work with a lot of these types of locks. Place the business card down in between the digit wheels. Turn the wheels one at a time. When you feel something catch on the business card, stop turning the wheel. Do this with each digit, moving the business card into the next gap, until you have stopped all the wheels where you felt the business card catch. Now, try pulling the opening catch back. The lock may spring open. If not, move each wheel around, one digit at a time, checking the lock after you have moved each wheel. When you have moved all three digits once, repeat the process until the lock springs open.

Try all possible combinations. It is the most time consuming solution, but you are guaranteed success. For a three digit code there are a total of 1000 solutions, including the triple zero at the beginning. It will only take a second or two to try each combination, as mostly you will only be moving one chamber by one digit to get to the next number. Numbers between the hundreds, like moving 345 to 346 for example, only take a single turn of one wheel. So, taking two seconds for each combination as an example, it would take 2000 seconds, or less than 35 minutes to open the lock. If you can remember whether your number was high, low, or neither, you can shorten the time by searching only likely combinations.


Write down your attache case's lock combination and keep it in your safe at home, for example. Keep it somewhere that isn't easily accessed along with your case and disguise the information within a longer number like a bogus phone number, for instance. Three-digit combination locks are relatively simple to open so, depending on what you keep in your case, it may be wise to make it safer. Fit it with a quality padlock and use a metal attachment that cannot easily be pried away from the case.


Only use these methods on your own attache case, unless you have the permission of the case owner.



About the Author

Steve Sparkes started writing professionally in 1982. He was a journalist and photographer for "The New York Waste" magazine for a decade. Sparkes has a diploma of art and design and a Bachelor of Arts in history of art from the South-East Essex School of Art. He also has a Master of Arts in photography from the London School of Printing and Graphic Arts.

Photo Credits

  • attaché-case image by Freddy Smeets from