Tuesday, November 15, 2005

Picking: A Delicate and Furtive Pastime

by Connie Wang (Class of '05)

It's cold, it's late, and you're locked out of your house. What to do? If this weren't your house, a brick through a back window would do. However, because you don't want to be grounded for the rest of your high school life, you need to find a resourceful way of letting yourself in quietly without causing any property damage or waking up your parents.

Luckily, you happen to keep a set of professional lock picks in a spiffy black leather case in your back pocket. The dark light on your front porch prevents you from being able to see what you're doing, so you must rely on your well-honed instincts to intuitively guess what's going on inside the lock. The locks on front doors are generally of the deadbolt variety, and use a cylinder (or pin) lock. A typical pin tumbler is a cylinder within a cylinder, with one rotating inside the other. A full rotation of the inner cylinder, also called the plug, turns the cam, which in turn physically unbolts the lock. Without a key, however, the full rotation is blocked off by a series of pins placed in an uneven line around the circumference of the cylinder. There is a set of pins at every point of resistance. A set of pins consists of two components: the uppermost pins are all of the same size, whereas the pins at the bottom are of varying lengths. In the context of the plug, there are small shafts for each pin set, with a spring at the top to hold the pin sets in place- the pins connect the inner plug and outer cylinder.

You have two main tools: a pick and a tension wrench. Picks are long, slender bits of metal that are curved or bent at the end, and you use these to reach into the opening of the lock to push the pins up. The tension wrench can be thought of as a delicate flathead screwdriver. Think of the tension wrench as your key, only without the ability to push the pins the right way. Whenever the tension wrench is pushed up against a set of pins, you must, with your pick, gently force that one set of pins up above the shear line. This set of pins has been successfully "picked." The process continues until all of the uppermost portions of the pins are up above the shear line, allowing the plug to rotate freely and unbolt the door.

You begin by putting the thin head of the tension wrench into the opening of the lock. Apply pressure gently in the direction in which you would rotate the key, turning until you can feel resistance. Without reducing the pressure, use your other hand to hold the pick. Feel around for the first set of pins that is obstructing your path. When you find the set of pins, use the bent end of the pick to delicately force up the bottom pin. You know you've succeeded when the spring yields, and the uppermost pin is resting in the outer cylinder while the bottom pin is in the inner cylinder. Now you are free to turn the tension wrench even more in the same direction as previously determined (that is, the same direction as how you would turn the key). Continue turning the tension wrench until you encounter resistance. Perform the same steps a few more times until you are allowed to rotate the entire plug, unbolt the lock, and slip in unnoticed to your quiet house.

1. http://www.lysator.liu.se/mit-guide/mit-guide.html
2. http://home.howstuffworks.com/lock-picking.htm

Links to this post:

Create a Link

<< Home