Recognizing and Exploiting Personality Traits 

Real locks have a wide range of mechanical features and defects that help and hinder lock picking. If a lock doesn't respond to scurbbing, then it probably has one of the traits duscussed in this chapter. To open the lock, you must diagnose the trait and apply the recommended technique. The exercises will help you develop the mechanical sensitivity and dexterity necessary to recognize and exploit the different traits.

Which Way To Turn

It can be very frustrating to spend a long time picking a lock and then discover that you turned the plug the wrong way. If you turn a plug the wrong way it will rotate freely until it hits a stop, or until it rotates 180 degrees and the drivers enter the keyway (see section 9.11). Section 9.11 also explains how to turn the plug more than 180 degrees if that is necessary to fully retract the bolt. When the plug is turned in the correct direction, you should feel an extra resistance when the plug cam engages the bolt spring.

 The direction to turn the plug depends on the bolt mechanism, not on the lock, but here are some general rules. Cheap padlocks will open if the plug is turned in either direction, so you can chose the direction which is best for the torque wrench. Wall padlocks made by the Master company can be opened in either direction. Padlocks made by Yale will only open if the plug is turned clockwise. The double plug Yale cylinder locks generally open by turning the bottom of the keyway (i.e., the flat edge of the key) away from the nearest doorframe. Single plug cylinder locks also follow this rule. See Figure 9.1. Locks built into the doorknob usually open clockwise. Desk and filing cabinet locks also tend to open clockwise.

When you encounter a new kind of lock mechanism, try turning the plug in both directions. In the correct direction, the plug will be stopped by the pins, so the stop will feel mushy when you use heavy torque. In the wrong direction the plug will be stopped by a metal tab, so the stop will feel solid.

Figure 9.1:Direction to turn plug

How Far to Turn

The companion question to which way to turn a lock is how far to turn it. Desk and filing cabinet locks generally open with less than a quarter turn. Locks which are separate from the doorknob tend to require a half turn to open. Deadbolt lock mechanisms can requre almost a full turn to open.

Turning a lock more than 180 degrees is a difficult because the drivers enter the bottom of the keyway. See section 9.11.

Gravity

Picking a lock that has the springs at the top is different than picking one with the springs at the bottom. It should be obvious how to tell the two apart. The nice feature of a lock with the springs at the bottom is that gravity holds the key pins down once they set. With the set pins out of the way, it is easy to find and manipulate the remaining unset pins. It is also straight forward to test for the slight give of a correctly set pin. When the springs are on top, gravity will pull the key pins down after the driver pin catches at the sheer line. In this case, you can identify the set pins by noticing that the key pin is easy to lift and that it does not feel springy. Set pins also rattle as you draw the pick over them because they are not being pushed down by the driver pin.

Pins Not Setting

If you scrub a lock and pins are not setting even when you cary the torque, then some pin has a false set and it is keeping the rest of the pins from setting. Consider a lock whose pins preer to set from back to front. If the backmost pin false sets high or low (see Figure 9.2), thgen the plug  cannot rotate enough to allow the other bins to bind. It is hard to recognize that a pin has false set because the springiness of the front pins makes it hard to sense the small give of a correctly set back pin. The main symptom of this situation is that the other pins will not set unless a very large torque is applied.

When you encounter this situation, release the torque and start over by concetrating on the back pins. Try a light torque and moderate pressure, or heavy torque and heavy pressure. Try to feel for the clikc that happens when a pin reaches the sheer line and the plug rotates slightly. The click will be easier to feel if you use a stiff torque wrench.

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