Locks are used on doors all around us; we use them in an attempt to limit access to particular places. The intent is for only someone with a key to having the ability to open a lock.
Lock picking is the pursuit of opening locks without the key. When a lock is picked, the lock’s parts are manipulated in order to release the locking mechanism as if a key was being used.
There are many types of locks, but the most typical lock construction includes a bolt or latch embedded into a door; when the mechanism of the lock extends the bolt into a space in the doorframe, the lock is closed and prevents the door from opening. A key controls the extension and retraction of the bolt.
One typical control inside a lock is a cylinder lock; in this mechanism, a key placed in the lock and turned rotates a cylinder. The rotation of the cylinder turns a part called the cam that controls the movement of the bolt’s extension and retraction. In order for the key to rotate the cylinder, it must be the correct shape and size.
This is because each lock contains parts called pins. The pins are aligned in a specific pattern that corresponds to the notches on the proper key; until the pins are manipulated by the key, they keep the cylinder from moving. The notches of the proper key will push the pins out of the cylinder; this in turn allows the cylinder to spin freely. Since you cannot see the pins, this can be fairly tricky to accomplish without a key.
In order to pick the lock, you need tools that allow you to access and manipulate the pins easily. Lock picks are long, flexible pieces of metal used to push all of the pins free of the cylinder. A tension wrench is a stiff, thin piece of metal used to slightly turn the cylinder in the direction the key would turn; this allows you to turn the cylinder a small amount in order to create a small amount of pressure where each pin meets the cylinder.
Then, the pick is used to lift each pin up and out of the cylinder; the pressure from the tension wrench causes a small clicking sound when this is accomplished. Once every pin is pushed free of the cylinder, it will turn freely and the tension wrench can be used to rotate it completely, opening the lock.
Not only are there many combinations of pin locks, there are many variations of them, some quite resistant to picking. Some have pins all the way around or have pins of different shapes. Each of these adds challenges to the already difficult picking process.
Locksmiths use additional tools when opening locks. A tool called a rake combines the tension wrench and pick into one and allows them to open multiple pins simultaneously. Others use electric pick guns that use vibrations to move the pins inside the lock. While no single tool is completely effective, with a complete arsenal an experienced lock-picker can open most common locks.