The common key used for the key switches in the 56 Series is the key number 60103
The standard common key number can be found by
Opening the product. Behind it, you will see a barrel number.
For example 123 or xxx etc.
Secondly that number has to be taken to a Master Lock Smith. Then request for an L&F key which starts with 60 followed by the barrel number.
I.e. 60123 or 60xxx
The key will then be produced by the Master Lock Smith, at the customers expense.
For further information please visit https://www.clipsal.com/Trade/search-results?q=56%20series%20key