How Master Keys Work 

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Your workplace and mine too has what looks like a million doors, and each entry has a key. Leaving the office late one evening I noticed that the maintenance personnel didn’t have a bunch of keys with them for the many rooms they were getting in and out of. It tickled my mind enough to get me searching. Well, what they use what is called a master key. If you are curious about how master keys work, as much as I was, read on.

Master keys are essential key systems to landlords and just like the example above, groups that need access to many doors but would be risky and tedious to hand them a key for each entry. So there is one convenient key that opens a multitude of doors; the master key. Sounds like a great invention so why did they not give you one master key for every entry in your home? Well, a master key lock system is also a risky thing to have.

A key that opens every door in your property requires top vigilance and security because if it falls in the wrong hands, it renders you a sitting duck of sorts. If this happened, you would need to change all the locks in your property or office which is a costly affair.

So how does a master key work?

Most locks have a pin and tumbler design kind of locking mechanism, the most common being the cylinder lock. The locking mechanism of a cylinder lock is sort of like a puzzle, which only its key can solve. Once you insert your key into your lock, the key turns a cylinder which then rotates a cam. This type of lock has a series of pins, that vary in length and are divided into two sets.  These pins rest on a shaft in the cylinder and have springs at the top that keep them in position.

When opening your door, the magic that happens is dictated by the grooves and notches on your key. These notches once the key is inserted into the lock, pushes the sets of pins to the designated shear line which opens the lock. That incorrect key you always seem to enter on your lock first, only aligns the pins partly in the plug and housing forming no shear line.

Locks that can be opened with a master key are designed to open with two different keys; the lock’s primary key and the master key. This lock has some of its pins separated by a third pin, known as a master spacer or wafer. This wafer is what does the magic to ensure that once a master key is inserted into this kind of lock, the pins will be raised to form a shear line too.

If you would like a master key lock for your home, you need to be very careful when purchasing one. If you buy it at your local hardware store, it is highly likely, that this master key will be available to other buyers in your neighborhood. The key is to ensure that your master key is as unique as it can possibly be so that you are not susceptible to break-ins.