Glossary Terms - K

Key Bitting Array

A matrix (graphic) display of all possible bittings for change keys and master keys as related to the top master key.

Key Changes

The total possible number of different keys available for a given type of tumbler mechanism. In master key work, the number of different Change Keys available in a given master key system.

Key Control

Any method or procedure which limits unauthorized acquisition of a key and/or controls distribution of authorized keys. A systematic organization of keys and key records.

Key Section

The cross-sectional shape or configuration applied lengthwise to a key blade that may restrict its insertion into the lock mechanism through the keyway. Each key section is assigned a designation or code by the manufacturer. A key section is usually shown as a cross section viewed from the bow towards the tip of the key.

Key Section

The cross-section of a key blade as viewed from bow to tip.

Key Side

The side of a door that is usually keyed. In the case of a nonkeyed function or one where both sides are keyed, it is the outside of an interior door.

Key Symbol

A symbol/designation that is used for a key combination using the standard key coding system.

Keyed Alike

(KA) - A group of locks all operated by the same Change Key. (Not to be confused with master keying)

Keyed Different

(KD) – A group of locks each operated by a different Change Key.


A term used in the hardware industry which refers to the arrangement of the locks and keys in a building or buildings into groups in order to limit the areas to which various personnel will be given access.

Keying Schedule

A detailed specification of a keying system listing how all of the cylinders are to be keyed.

Keying Schematic

A chart that visually shows the levels and layout of a key system.


A set of buttons with numbers, letters or symbols used to manage access with a PIN (personal identification number) or pass code.


The broach or aperture in a cylinder plug that is formed to match that of the key blank section being used.


A round handle on a door, generally used to actuate a lock or latch but may be used simply as a pull or dummy trim.