What is a Bump Key
Tuesday, June 12th, 2007 Subscribe To Our Feed
Another method for defeating this type of lock is known as bumping. In this method, a key blank that fits the target lock is specially cut, with all the cuts at or slightly below the deepest level for a key made by the manufacturer, and a small amount of material removed at the tip, and, where applicable, at the shoulder - the part of the key that prevents the key from entering the lock too deeply. This allows the key to be inserted slightly farther into the lock than normal. The key is inserted into the target lock to normal depth, and by striking the head of the key while applying slight torsion, the lock can be opened in seconds.[1] This method emulates the snap gun approach with decidedly simpler tools — the special key and a device (e.g., mallet, screwdriver handle) to deliver the blow. When used with criminal intent, bumping often does not allow the victim to make a successful insurance claim because it leaves no sign of forced entry.
For exemple, Medeco locks are bump-proof with the sidebar, but Mul-t-lock locks can be open by bumping in seconds (Mul-t-lock Classic, 7×7 and Interactive are subject to bumping).
Bump keys, like electric pick guns and snap picks exploit impulsive impacts on the pin stack, as described above, to open the lock quickly and effectively.
