Door locks are a minor inconvenience to anyone who knows how to use a bump key. Bump keys are blank keys that can be cut to a special design that allows a user to use it for picking pin tumbler locks. Pin tumbler locks a very popular kind of lock, it includes an exterior door entry locks for homes.
Bumping is the process of gaining entry using a bump key. All the cuts on a bump key are made to the maximum depth, so any key blank can be made into a bump key. Bump keys are also manufacturer specific. For example, a Kwikset lock requires a bump key made from a Kwikset key. The same is true for other lock brands.
There are 2 methods when using a bump key. One is the pull back method which is common and the other is called minimal movement. With the pull back method, the key is inserted all the way in, and then pulled back out one notch. While keeping rotational pressure on the key, it is then bumped into the keyway with the heel of the hand or with a device of some sort.
The minimal movement is slightly more sophisticated than the pull back method. Bump key performance can be improved by filing away an additional 0.25 to 0.5 mm from the key tip and shoulder, allowing the key to be inserted slightly farther into the lock.