Chapter 4
Basic Picking & The Binding Defect
The flatland model highlights the basic defect that enables lock picking to
work. This defect makes it possible to open a lock by lifting the pins one at
a time, and thus you don't need a key to lift all the pins at the same time.
Figure 4.3 shows how the pins of a lock can be set one at a time. The first
step of the procedure is to apply a sheer force to the lock by pushing on the
bottom plate. This force caused one or more the of pins to be scissored between
the top and bottom plate. The most common defect in a lock is that only one pin
will bind. Figure 4.3a shows the left pin binding. Even though a pin is binding,
it can be pushed up with a picking tool, see Figure 4.3b. When the top of the
key pin reaches the sheer line, the bottom plate will slide slightly. If the
pick is removed the driver pin will be help up by the overlapping bottom plate,
and the key pin will drop down to its initial position, see Figure 4.3c. The
slight movement of the bottom plate causes a new pin to bind. The same procedure
can be used to set the new pin.
Thus, the procedure for _one pin at a time picking_ a lock is to apply a sheer
force, find the pin which is binding the most and push it up. When the top of
the key pin reaches the sheer line, the moving portion of the lock will give
slightly, and driver pin will be trapped above the sheer line. This is called
_setting_ a pin.
Chapter 9 discusses the different defects that cause pins to bind one at a time.
1. Apply a sheer force.
2. Find the pin that is binding the most.
3. Push that pin up until you feel it set at the sheer line.
4. Go to step 2.
