A bump key is a normal key that has been modified. It’s a device used to gain access into a home entry lock. These keys can be purchased on the Internet, however, you can also try and make them at home. To make bump key devices work, the modified key must be made based on the shape of a target key.

Bump keys should have new cuts that are below or at the same level as the deepest cut on the target key. Some bump keys need partial removal of the tip as well as the part that does not slide into the lock. If a key isn’t filed down properly, it may stick in the lock. The key being modified must also fit into the lock prior to being filed down.

Normal keys have ridges on them that line up with the pins inside locks. When the heights on the bump key’s ridges line up with the heights on the pins, the cylinder on the lock will catch. As the bump key is pushed into the lock, the energy from the push is transmitted to the pins, and the cylinder turns.

To make bump key devices fit properly into the target locks, it’s best to use a triangular file for shaping. Make a pen mark at each valley on the key to be filed. Mark inside the indented line, so there is a point of reference once you begin filing. Note the lowest level, because each valley will be filed to that point. Shave off the metal of each ridge until you form v-shaped peaks.

Bump keys will work on any locks they originally fit into. They are the ideal tools for police, fire and other emergency departments. These devices provide numerous advantages whether you use them as skeleton keys or for various emergency needs.