OVERVIEW
Master key information is important if you’re going to use a master key for your house’s security system. Although relatively simple in function, master keys can only work on certain types of locks, which is why you should know how their internal mechanisms work. So if you are looking for this information then the following will show you what you need to know.
A QUICK REVIEW OF HOW LOCKS WORK
In order to understand how master keys work, we will first need to review how locks work. The main component of the average pin and tumbler lock are their pins. These pins are of varying length and divided into several pairs. Each pair of pin is situated on a shaft which runs through a central cylinder plug.
When there is no key in the lock, the bottom pins are kept in the plug, while their upper counterparts are partly kept in the plug and partly in the housing section of the lock. The purpose of the upper pins is to prevent the cylinder plug from being turned by binding them into the housing.
When a key is inserted into the lock, its notches push the all of the pins until each pin pair lines up with the space where the lock’s cylinder and housing come together. This point is known as the shear line, and lining up the pins along this line allows the opening of the lock. On the other hand, if an incorrect key is inserted then part of the top pins will still in the plug and housing, thus preventing the lock from being opened.
HOW DO MASTER KEYS WORK?
Now that we’ve reviewed how locks work, let’s go back to the topic of master keys. It’s worth mentioning that certain types of locks are designed to accept two keys, namely change keys and master keys. The change key only opens one specific lock, whereas the master key can open all of the locks in a particular set.
This feature is made by possible by the existence of a third pin, which separates some of the pin pairs. When there are three pins in a particular shaft, they can be positioned in two ways, so that they will be able to open the lock. The first method involves the change key, while the second one involves the master key.
In the first scenario, the change key simply raises the pins until the shear line rises beyond the master wafer. On the other method, the master key works by raising the pins until the shear line is below the master wafer. In either case, a gap in the shear line is created and the key can be turned. This kind of mechanism allows any person who holds the master key to access any lock that belongs to the same set.
Give the nature of these kinds of locks, they are more vulnerable to bump keys, since they can accessed by two sets of keys and not just one. So if you’re going to install locks which respond to master keys in your home, be sure to exercise extra caution in securing your keys.
