Binding

=Binding=

Binding is a fundamental principle of locks that prevents the lock from opening without the correct key. Binding is also used in lockpicking and impressioning to allow components to be manipulated individually. A tension tool is used to bind components and determine the order in which they should be picked, or, in the case of impressioning, the spots in which a key should be filed.

In lockpicking
The type of binding that occurs during lockpicking is depends on lock design, the lock components (pins, wafers, discs, etc) and the lock body. In cylinder based locks, binding is caused by the cylinder and plug shearing into components. Binding not only determines the order in which components are picked, but also holds them in position so that they can be individually manipulated.


 * Pin-tumbler and Wafer locks
 * Binding occurs between pins or wafers, cylinder, and plug.


 * Lever locks
 * Binding occurs between the levers and the bolt, stump, or fence.


 * Disc-detainer locks
 * Binding occurs between the discs and the sidebar.


 * Combination locks
 * In direct-drive rotary combination locks, binding occurs between the combination wheels and the fence. Also applicable to many low-security combination padlocks where the shackle binds with the wheels.

In impressioning
Impressioning uses binding to freeze components in place so that a blank key can be used to determine proper position of components. Almost all impressioning techniques apply extreme tension to bind all components in the lock then use a blank key to obtain impressions. This is true for pin-tumbler, wafer, lever, and disc-detainer locks.

In warded locks, the blank key binds directly against the wards of the lock to determine where to remove material from the key.

In decoding
Various forms of decoding use binding to identify components in the incorrect position. In most lock designs a component that is no longer binding is properly positioned and can then be decoded. Impressioning, mentioned above, is one such example.