Master Key Cylinders

The diagrams below detail how the various keying systems operate. When considering a master keying system for a building, it is important to maintain a balance between the level of security needed and the accessibility.


Keyed to Differ (KD)

A cylinder which is individually keyed. ASSA ABLOY cylinders are supplied to differ as standard, unless otherwise stated.


Keyed Alike (KA)

In a KA system multiple locks and cylinders can be operated by the same key.


Master Keyed (MKD)

Indicates that designated locks can be manufactured to be operated by two different keys, one, the "Servant Key" operates individual locks, whilst the "Master Key" is able to open all the locks in the suite.


Grand Master Keyed (GMKD)

In a GMKD system there is a control key which operates a number of locks which are further controlled by a sub-master key which can only operate keys in a particular grouping. There can be multiple groups controlled by the control key.

Find out more about this product range:

Contact Us