Safe-deposit locks are a standard type of lock that secures a box, usually covered with protective steel. They are often used for special and important documents or important and valuable mementos. Many banks have safe-deposit boxes that use these kinds of locks; however, there are some safe-deposit boxes that you can have in your home. Wherever the safe-deposit box is, there is a specific way to drill them so that you do not trigger any backup locks and do not damage the contents.
Make sure you have an adequate drill. You will need one that is capable of burrowing through solid layers of metal. Metal drills can be expensive, but they are the only tool that can break through a strong lock like the safe-deposit lock. Make sure your drill is either plugged in or fully charged because you will need all the energy that you can get when trying to drill a safe-deposit lock.
Mark three "X's" on the safe-deposit lock with chalk. These three "X's" should be over both keyholes and one to the far left of the lock. On most safe-deposit boxes, the hinge will be on the right; however, if it is on the left, then the third "X" should go on the right side instead. It should be next to the edge of the box door on the side opposite the hinge.
Drill the two keyholes first. Drill about 1 inch inward. This should break through the locked key hole entirely. The keyhole may be a little more shallow; if this is the case, drill 1/4 inch at a time, checking the keyhole each time. When you can see the locking mechanism, you should stop drilling.
Place the drill bit over the third "X." Drill all the way through, until there is no more resistance. You do not have to be as careful on this "X" because it should be far to the edge of the contents of the box, which means they are in no danger of being damaged. This will break the lock bracer that is holding the door shut. Doing this will allow you to swing the door open. As long as you drill in these "X's" only, you should have no problem.