Bitting is the depth of key cuts on a cylinder key for a

pin tumbler lock The pin tumbler lock, also known as the Yale lock after the inventor of the modern version, is a lock mechanism that uses pins of varying lengths to prevent the lock from opening without the correct key. Pin tumblers are most commonly employ ...

, often expressed as a number. Bitting also refers to the combination of key cuts on a

bit key The bit is the most basic unit of information in computing and digital communication. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represented as ...

for a

warded lock A warded lock (also called a ward lock) is a type of lock that uses a set of obstructions, or ''wards'', to prevent the lock from opening unless the correct key is inserted. The correct key has notches or slots corresponding to the obstructions i ...

lever tumbler lock A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or '' fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load, and effort, the lever is ...

. The exact geometry of modern keys is usually described by a code system. The bitting instructs a

locksmith Locksmithing is the work of creating and bypassing locks. Locksmithing is a traditional trade and in many countries requires completion of an apprenticeship. The level of formal education legally required varies by country, ranging from no formal ...

how to cut a certain key, to replace a lost key or make an additional copy. The bitting is usually a series of integers (e.g. 372164) that is usually translated from a key code chart or from a bitting code list to settings on specially designed key machines. In many code systems each digit in the bitting corresponds to a certain location on the key blank where a cut or notch is to be made and also indicates the necessary depth of the cut. Many lock companies use their own proprietary code system. Depending on the maker, the bitting sequence can be from bow-to-tip (the bow being the larger, handle portion of the key), or can be from tip-to-bow. A smaller number is typically a shallower cut on the key, but not always. Assa bitting codes are reversed, where the higher the digit, the shallower the cut. One American manufacturer, Eagle Lock Company, used letters exclusively for bitting codes.

Angularly bitted

This is a type of key where the individual cuts are designed to engage

chisel A chisel is a hand tool with a characteristic Wedge, wedge-shaped cutting edge on the end of its blade. A chisel is useful for carving or cutting a hard material such as woodworking, wood, lapidary, stone, or metalworking, metal. Using a chi ...

-pointed pins in high-security locking systems manufactured by Medeco and Emhart. These angled cuts are designed to lift each tumbler to a predetermined height to the shear line and to rotate them to a specific angle to engage a sidebar mechanism (Medeco) (this is also used in Schlage Primus) or to line up an interlocked pin to such a position to where it would allow the plug to rotate (Emhart).

References

{{Locksmithing Locksmithing

Angularly bitted

See also

References