How do master keys work?
This is one of the most common questions we get asked, so we thought we'd put together a little video for you to understand a bit more about master-keying and how it all works. So grab yourself a cuppa and let us take you through this simple process with a short video demonstration!
The concept of master-keying has been around for centuries, but it is only in more recent times that they have become widespread for business owners and even home-owners alike.
Master-keying does exist for lever-type locks, but is generally not as secure and is a far more restricted approach, and therefore master key systems nowadays are most commonly seen using cylinder operated locks.
In principle, the idea is that a lock that needs to be opened by its own unique key AND a master key, effectively needs two sets of pins, one for the individual key, and another for the master-key. But of course, these pins need to both be in the same place. This is where master-pins come into play, which are effectively smaller pins which sit on top of other pins to add more cut-depth possibilities for the keys.
So, if you imagine Key#1 has cut-depths of 5,2,5,4,5,6 (six cuts so this would be for a a six-pin cylinder), and the master-key had cuts of 3,6,5,4,1,2 then you would effectively find the lowest cuts from both Key#1 and the Master Key, and use these as the first row of pins.
In this scenario, the first row of pin sizes would need to be 3,2,5,4,1,2. This row of pins technically wouldn't allow either of the keys to open the cylinder, because these pins don't match all of the cuts on either key. But this row of pins allows for the smallest cuts to all work, meaning all we have to do is float additional pins on top of these to make up the differences.
So for the second row, we'd need to add the following pins: 2,4,--,--,4,4. By adding these secondary pins on top, the first pin can now accept cuts of 3 or 5, the second pin will accept 2 or 6, the third and fourth didn't need any additional pins, so will take the required cuts of 5 and 4 respectively, then the final two pins will take 1 or 5, and then 2 or 6.
You'll now see that this array of pins accounts for both the master-key's cut depths and the individual key's cut depths (Key#1). So both keys will work in this lock.
Repeat this process for a dozen different locks with their own unique keys, but the same master-key, and you'll get the same outcome - each lock will have its individual keys still, but the master-key will also work!
Any questions? Get in touch! We're happy to answer them :-)