How to Create Bump Keys for Disk Locks

One properly made bump key can open a variety of locks.

Bump keys work by allowing a locksmith to disassemble a lock much more quickly than with a standard pick. This type of key may be cut from either a new or used key. The object of creating a bump key is to cut off parts of the key so that only sharp-peaked, deep ridges remain. This can be accomplished using a key cutting machine. But if you do not have access to one, it is possible to make the key using a file.

Things You'll Need

• Blank or used key
• Key cutting machine or file

Instructions

1. Cut or file down the key's ridges so they are at their maximum depth, generally referred to as "depth nine." When finished, the remaining ridges look very pointy.

2. Cut off the very tip of the key, making it slightly flat in front. Cut off a small piece of the top of the shoulder, or the part of the key that does not get inserted into the lock.

3. Use the key by inserting it into the lock. Tap the key firmly, but not forcefully, with a butter knife or spoon. If done correctly, the lock disengages. If too much force is used, the bump key or the lock may become permanently damaged.

Tips & Warnings

• Only use a bump key to open locks that you own.

References

• DPC Productions: How to: Bump Key