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To understand how a lock pick works, you first must understand how a lock words. The most common type of lock found in residential homes and businesses is a cylinder lock, which needs a key to rotate. Rotating the cylinder lock unlocks it or locks it. Inside a cylinder lock are tubes that run through the cylinder and into the surrounding housing. Inside each tiny tube is a pair of pins, one on top of each other. Each pair of pins is of a different height. At the top of each tube, or shaft, are springs that hold the pairs of pins in place. The bottom pin rests completely inside the plug, while the upper pin rests halfway inside the plug and half in the surrounding housing, This positioning keeps the lock from rotating, and keeps the door or item locked.
A key inserted into the lock will push the pins up to different heights, depending on the notches on the key. The pins must be pushed up to the exact height that will clear the line where the cylinder and housing meet. All the upper pins will be in the upper housing, and the lower pins in the lower housing. This will allow the cylinder to rotate, unlocking the door or other item.
Lock Picks and Tension Wrenches
Lock picks work by enabling the user to move each pin pair into the position that allows the lock to open, as discussed above. The pin pairs must be moved one at a time.
Lock pics are long, very thin metal tools that curve up at the tip. They are designed to go into a lock and push each pair of pins up. To pick a lock, however, a tension wrench such as a thin flathead screwdriver must also be used. The purpose of the tension wrench is to twist the plug slightly, which creates a small ledge because the cylinder becomes offset from the housing.
Using the Lock Pick
To use the lock pick, you apply pressure with the tension wrench while inserting the pick into the hole and lifting the pins one at a time. If done correctly, you will hear (some people feel it) a soft click when the top pin moves all the way up into the housing. This clicking sound is actually the top pin settling on the small ledge, which holds it in place. As you push the upper pin in, the lower pin will come to rest down in the plug. Once all of the pin pairs are in place, the lock will open.