This video covers the complete process for changing and setting the combination of a 5-button Simplex lock.


For unknown reasons, the full details of how to set combinations with this lock were lost for years—even to Dormakaba, the manufacture. At the time of posting my video (June 23, 2020), no one had yet recorded a proper tutorial for users of the Simplex lock. The YouTube channel for Dormakaba had no detailed tutorial on the subject, and all printed instructions I had found with handgun safes were incomplete. Mine is the first complete tutorial on how to set combinations with a 5-button Simplex lock.

I recommend that first-time users practice setting simple combinations after watching this video, so that the process becomes less intimidating and more familiar. Play with it. These locks are designed to withstand heavy use. You will not harm your lock by setting and resetting combinations.


The 5-button Simplex lock allows for a total of 2,162 possible combinations. For an understanding of the mathematics, see my video, “How Many Combinations Are Possible With a Simplex Lock?" The video introduces the subject of combinatorics, and offers an easy to understand method for calculating the total combinations possible using the 5-button Simplex lock.


Before I posted this video on June 24, 2020, not a single correct calculation of the total combinations possible using the 5-button Simplex lock had been performed. At least, the evidence was not available anywhere in writing or in video posted online. I had seen the figures 1,081 and 1,082 proposed online, though neither of these estimates were correct.


The second figure, 1,082, was particularly troubling to me, considering that the math instructor who proposed that number included the null combination, which involves pressing no buttons. Properly speaking, if one is not actuating any buttons, one is not actuating any portion of the internal mechanism responsible for releasing the lock from the locked state, and therefore one cannot be said to be "using" a combination to open the lock.


This is not to say that no one was capable of solving the problem. Students of combinatorics and their instructors have had the knowledge to tackle the problem since the Simplex lock was invented. Unfortunately, every attempt to calculate the number of possible combinations had been made by individuals who knew nothing about Simplex locks. Locks were not their field. Math was.

Thus, as a result of being in the right place at the right time, and of having an interest in math (though no degree in the subject), I have had the unique privilege of being the first to present a clear method by which to calculate the total number of combinations permitted by the Simplex lock, and then to share that final figure which has been the subject of speculation for decades.


The 9600-Series Simplex lock has a design feature that protects the lock should someone force the knob to turn when the lock is in the locked state. The knob, which is made of steel, has a set of moving parts inside that allow the top portion of the knob to slip one quarter of a turn each time the knob is forced. A pair of ball bearings draw up into the body of the knob, the knob turns, then the ball bearings snap into one of two pairs of holes.

This feature will protect the lock from attempted forced-entry, and the ball-bearing assembly will withstand this treatment for years. Put plainly, the 9600-Series lock is made to take abuse.

This video was recorded on July 5, 2020.


At one time in the early 2000s—before KABA merged with Dorma to form Dormakaba—KABA was facing legal trouble because locksmiths had found that the 1000-Series Simplex door locks could be bypassed using a strong rare-Earth magnet. A critical component of the locking mechanism was made of ferrous material, allowing the lock to be compromised easily and covertly.

However, new Simplex locks like the 9600-Series locks installed in handgun safes are not vulnerable to attack with a magnet. Since I still answer questions about this issue, I have recorded a simple video to reassure people with lingering doubts about the lock. It’s titled, "Can a Simplex Lock Be Opened With a Magnet?"




What you should know before buying a handgun safe.

Handgun Safe Research is on YouTube. Subscribe and keep up with the latest findings. is a security-testing resource that evaluates firearm safety devices.

handgunsaferesearch_Green copy.png

what you should know before buying a handgun safe