CPL Master Key System Architecture 3

Question 1

In a master key system bitting list, what does the column labeled 'MK' typically represent?

Accepted Answer

The master key bitting for that group

Answer

The 'MK' column in a bitting list records the master key bitting depths used as the controlling bitting for a group of change keys.

Question 2

What is 'maison keying'?

Accepted Answer

A system where one key opens many locks but each lock has its own unique key

Answer

Maison keying (also called 'hotel keying') allows a single entry key to open multiple units, while each unit also has its own individual key.

Question 3

When designing a master key system, what does 'total bitting list' (TBL) analysis help prevent?

Accepted Answer

Duplicate key cuts that would cause unintended cross-keying

Answer

A total bitting list analysis compiles all key bittings in the system to identify and eliminate duplicate or conflicting bitting combinations that could cause cross-keying.

Question 4

What is the role of a 'sub-master key' in a tiered master key system?

Accepted Answer

It operates a defined subset of locks within a master key group

Answer

A sub-master key is positioned below the master key in the hierarchy, controlling a specific subset of locks within a larger master key group.

Question 5

In a six-pin cylinder master key system, what is the maximum theoretical number of usable change key combinations using a progression increment of 1 across depths 1–9?

Accepted Answer

9^6 minus unusable bittings

Answer

While 9^6 = 531,441 combinations exist mathematically, real-world usability is reduced by MACS violations, cross-keying conflicts, and progression rules, leaving far fewer usable bittings.

(CPL) Certified Professional Locksmith Practice Test

(CPL) Certified Professional Locksmith Practice Test

CPL Master Key System Architecture 3