Master key system

Master key system (MK-system)

Master key systems are those locking systems in which all cylinders that occur can be locked with a common key (master key).

1. Example

Master key system


The following closures can be seen in the 1st picture:

  • keys S.1 to S.11 close the corresponding cylinders (doors) Pos. 2 - Pos. 10
  • key S.1 closes all cylinders (master key)
  • the number of the respective keys does not play a role


2. Example: C/MK system (central master key system)

Central master key system


The following closures can be seen in the 2nd picture:

  • in addition to the 1st example, all existing keys also lock the central areas: front door and cellar door
  • as in the 1st example, there is one master key that closes all cylinders
  • Note: If the master key is to lock the apartments, you should have written consent from the tenants. We assume the presence of this consent in the production of locking systems!