Things that Go Bump in the Night (or Day)
By Jim Hancock

Bump keys. Lock bumping. It's the rage, it's the hot topic for every talk show, news agency, homeowners association meeting and anyone it seems trying to strike fear in the hearts of the public regarding their security. It is the latest and greatest craze of hobbyists that spend their time try-ing to defeat locks. Due to this sudden surge in populari-ty, many in our profession are seeing an increase in sales of "High Security" locks and getting inundated with calls from concerned consumers wanting to know how to stop this action from compromising their homes and business-es. Sadly, many in our industry are taking advantage of the public by fanning the flames of their fear and using this as a means to peddle high end products that are being used on doors that are worth less than the locks. Lets take a look at the bump key and lock bumping, how it works, and how we as professionals can make locks more resistant to bumping without overselling a product.

HOW IT WORKS
Lock bumping has been used as means of bypass for decades. It is certainly not new and as bypass methods go, it would not be one of the top choices used by most of us. Though it does work, and quite well on some types of lock, it lacks the professionalism exhibited when picking or raking or impressioning or even using a pick gun. To understand how it works, lets think for a moment about how a pick gun works. When using a pick gun, we insert a tension bar into the lock and apply light tension to the plug, Creating a light bind on the pins. (pic #1) Then we insert the pick gun tip, and squeeze the trigger.(pic#2) If everything is done correctly and with some degree of luck, after a few pops of the gun, the lock will open. This is based on the same principal as used in croquet or bil- liards. If you visualize the bottom pins as the cue ball and the pick gun as the cue stick you will understand this readily. When you strike the cue ball with the stick, the ball moves. When it strikes a second ball, (the drivers in the lock) with the proper touch, what occurs? The cue ball stops where the cgntact is made and the second ball moves onward. When you pop the bottom pins, with the proper tension on the lock, the bottom pins are hammered against the drivers. The bottom pins stop in place while the drivers are knocked upward. If your ten- sion is right, the drivers are driven above the' shear line and this allows the lock to turn. A bump key, or bumping the lock works using the same premise. With a properly cut bump key and using the correct technique, the bottom pins are hammered against the drivers, creating separation and voila! A shear line.

BUMPING A LOCK
In order to bump a lock, the first thing needed is a proper- ly cut bump key. This is the catalyst in a successful bump attempt. So what is a properly cut bump key? If you stop and think mechanically for a moment what you are attempting, it should become clear what is need- ed. Since the shear line is created by separating the bottom pins and drivers at the top of the ; plug, you need a key that will not push any of the bottom pins above the plug surface with sim- pie insertion. So a proper bump key is one that con- rains the deepest cuts available for the particular manufac- turer you are opening. And since we are attempting to shear 5 or 6 pin cylinders, this key should be comprised of the deepest cut all the way down the blade. (pic #3) But the real key (no pun intended) to the bump keys success is not just the cuts but the peaks between the roots of the cuts.(pic#4) It is the peaks that will drive the pin stacks.

With a properly cut bump key in hand, you now need something to "shock" or "rap" the key with. In order for this to work, you are going to have to immolate the actions of a pick gun. In other words, a rapid and sharp blow to the pins. You can not merely by hand accomplish this. What you use to strike this blow will depend on a couple of factors: (1) what you have available and (2) what you use to apply tension to the key. Because bumping, like picking et al, requires tension on the plug, you will need something to tension the key while striking it. Most of us that bump locks simply use our fingers. They are conven- ient (always have them with us, hopefully) and we get a better feel on the lock. Having said this, what I do not want to do is use a hammer as a striker. A finger when hit by a hammer hurts. A finger when hit while pinching the head of a key, hurts exponentially. What I generally use is the handle of a weighty screwdriver.(#5) This is generally  plastic and provides the proper shock to the lock while  providing little shock to me when I miss hit the key.   Now for the actual operation. First, insert your bump key into the lock all the way to the shoulder stop then back the key up by one space. (#6 & #7) Again, visualizing what is happening inside the lock, pin stack #1 is seated in cut #2, stack #2 is in seat#3, etc. The last stack in the lock, 5 or 6, is actually not seated in a cut at all but rather it resting on the tip angle of the key. With the key in this position, you now will put light turning pressure on the key.(#8) If using your fingers, the tension is light, do not go "white knuckle" on the tension. Just like pick-ing, raking etc., too much tension defeats the purpose.

With tension applied, use whatever striking device you choose and strike the end of the key.(#9) The strike should be sharp and firm but you are not trying to drive in the winning run in the bottom of the 9th. Sharp and firm, not heavy and hard. If the cylinder does not turn, while continuing to hold some tension, pull the key back out by one space and repeat the operation. You can gener- ally tell if you are shearing any pins when you try retract- ing the key after each strike because if you have pins sheared, pulling the key back becomes a struggle as the bottom pins can not move smoothly between the chamber in the plug and the now offset upper chamber. Struggling to retract the key could also indicate too much tension on the key. You may do this 2 or 3 times before it opens, you may spend minutes on it and it may not open at all. Happy striking!

HOW CAN WE MINIMIZE LOCK BUMPINGS EFFECTIVENESS

First let me say that lock bumping in my opinion is not being widely used as a method of entry by the criminal element. Lets face it, most people in this line of work do not concern themselves with salvaging a lock to be used after entry is made. They will avoid the locked door com- pletely if there is a perfectly good window or sliding patio door available. But thanks to the proliferation of videos being posted on the internet by hobbyists that bypass l ocks for fun, common folks that just want to try it, news media that sensationalize it as the wave of the criminal future, and of course word of mouth and innuendo regarding break-ins around town, we in this profession as stated earlier are being asked by the public to offer solutions to this men- acing issue.

is that if they still retain patent rights, the blanks are not readily available. Also, anytime you are attempting a bypass where you are not creating a simple shear line but also have to manipulate a secondary action or shear line, such as in Medeco where the pins not only have to raise to the proper height but must rotate to allow a side bar to shear, humping just became almost impossible.

The easiest and quickest way to lesson the effect of lock bumping is to sell and install "High Security" locks such as Medeco M3, Mul-T-Lock, Assa, Primus. These locks resist bumping for several reasons, not the least of which

But what if the door that this lock is being utilized on is  not substantial enough for such a heavy duty lock? Or   more often perhaps is the scenario where the fear far out- weighs the likelihood of the occurrence. In other words, say an apartment dweller is concerned about bumping. The noise alone of bumping would almost certainly pro- hibit bumping as a "break-in" method of someone in an  apartment setting with neighbors so close. But our job is to protect the public and make them as secure as possible without taking advantage of them. So how do we accomplish this? Here are some suggestions:

Since the success of the bump key relies on that hammer effect of the bottom pins bouncing the driv- er above the shear line while the bottom pins themselves remain below plug level, it could be reasonably assumed that if we use the deepest'pin avail- able in the brand of lock we are working with ( a 9 for Schlage, 0 for Sargent, etc) that when a bump is attempted, the longer bottom pin will perhaps jump enough to cross plug level and block the shear line, thereby thwarting the bump attempt. Following the same logic as above for why bumping works, it can also be assumed that using a stiffer spring combined with a longer than normal driver would be effective. Because of the longer travel required for the longer driver and the stiffer resistance of the spring, the hammer effect does not work as well.

Spool and mushroom type drivers will also prohibit bumping from being as successful for the same reasons they confound normal picking and raking. The combina-tion of tension applied to the cylinder and the abnormal shape of the driver tend to cause the driver to get caught up at the shear line in the void of the pin surface.

These are just a few of the ways we can service our cus-tomers needs and alleviate their fears concerning bump keys. They are quick and simple measures and less costly for the customer than replacing existing locks with some- thing that may be overkill. Let me close by saying again that I do not believe that lock bumping has replaced breaking a glass, opening a patio door, jacking a door, using unauthorized duplicates or any other of the myriad of means used by the criminal element to breach a house or business. It is simply the water cooler topic of the moment and we as an industry need to be able to deal with it fairly.