I always recommend that my Buyer clients change the locks on the houses that they purchase after they own the home. You never know who had a copy of the key to the house, so if you want to have some increased peace of mind, change the lock.
Then I heard about bump keys and now I’m not so sure about that peace of mind. While bump keys have been around since the 1920s, they were more of a mainstay to locksmiths. With the increased sense of people being entitled to things that don’t belong to them, however, bump key usage by the general population is now on the rise.
What is a bump key?
Most cylinder locks have tumblers, in which metal pins need to rest at an exact height in order to open the lock. You insert your key, which tumbles the pins to the right height, and voila! You’re in. Bump keys have jagged teeth set really low so they fit into a lock tumbler. The jagged teeth of the key, when “bumped” by applying force and torque, make the pins in the tumbler bounce into the exact position needed to allow the lock to be opened.
There are numerous sites on the web that teach you how to make bump keys. Some of them have a small note that implores you not to use them to unlawfully anyone’s property, but with as easy as the information is to access, it’s good to prepare yourself, and your locks.
Great. So how do you stop that?
Pickbuster is one product advertised online that has mixed reviews. It’s a substance that you spray into the lock that supposedly won’t allow the pins to be bumped enough to engage the lock. Reviews of it don’t support its efficacy though.
Additional locking mechanisms, such as sidebars or sliders may thwart bumping. Additionally, locks with non-pin tumbler locking mechanisms stop bumping. Disc detainer, combination, wafer, warded, and level based locks are all immune to bumping.
The short story?
It’s still a great idea to change the locks on your new house but it would be even better to do some research before you rush out and buy the first lock that’s on sale.