How to Open a Four-Digit Combination Lock

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With all the passwords, usernames and entry codes needed to be remembered as you go about your day in the constantly-changing technical world, remembering the code to a combination lock can be tricky. If you have forgotten the sequence to a four number combination lock, it doesn't mean the lock is no longer useful or that your item is forever secure. There are many ways to safely open an otherwise secure combination lock.

How to Open a Four-Digit Combination Lock
Image Credit: Fernando Trabanco Fotografía/Moment/GettyImages

Four Number Combination Lock Details

It's simple yet effective and more secure than its three-digit combination lock counterparts. Four-digit combination locks are made to last. There is one wheel for each number. When the dial is turned, the spindle that connects each wheel rotates the drive cam. A drive pin that is attached to the drive cam makes contact with the tiny tab on the wheel fly that is adjacent to the wheel. There is a wheel fly on each side of each wheel. The drive pin is responsible for having all the wheels make contact. When the correct combination is entered into the lock dial, all the notches on the wheels line up on the spindle and the lock pops open.

How to Open a Four-Digit Combination Lock

To set a combination lock, place the dial at 0 to begin. Use the reset tool that came with the combination lock and push it into the hole on the side of the lock chamber. Turn it 90 degrees in either direction. Set the wheels at the combination you've chosen. Try to choose something easy to remember and specific to you but that isn't easy for others to guess, such as a birthday. Remove the reset tool and you and your lock are all set. Some of the more reliable locks on the market include Puroma and Master Lock. The Puroma combination lock instructions are readily available online for troubleshooting or setting a four-digit combination lock.

What to Do if You Forgot the Combination

A good combination lock can make you feel secure when you have to walk away from your belongings or ensure that they are safe while you sleep or work. When it refuses to release its chambers to allow you access to your things, it can be frustrating. If you forgot a bike lock combination or the digits to a padlock with a dial, you can try to reset it. Pull on the shackle until you see the wheels turn. When the wheel sticks or catches, move to the next wheel and continue through all the wheels. They will barely stop at the combination so this process takes quite a bit of patience.


Kimberley McGee is an award-winning journalist with 20+ years of experience writing for a variety of clients, including The New York Times, Las Vegas Review-Journal Home section and other national publications. As a professional writer she has researched, interviewed sources and written about home improvement, interior design and related business trends. She earned a B.A. in Journalism from the University of Nevada, Las Vegas. Her full bio and clips can be viewed at

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