CRL Master Key Systems & Key Control 1 — Questions and Answers
Question 1: In a master key system, what is the function of a 'change key'?
- It opens every lock in the system
- It opens only one specific lock within the system (Correct answer)
- It is used to re-key all locks simultaneously
- It overrides all other keys in the system
Correct answer: It opens only one specific lock within the system
A change key (also called a servant key) is cut to operate only one specific lock within a master key system.
Question 2: What term describes a key that operates all locks within a specific group or section of a master key system?
- Change key
- Control key
- Grand master key
- Master key (Correct answer)
Correct answer: Master key
A master key is designed to operate all locks within a specific group or section, sitting one level above change keys in the hierarchy.
Question 3: In a master key system hierarchy, what does a 'Grand Master Key' (GMK) operate?
- Only executive suites and restricted areas
- Only one specific high-security lock
- Multiple groups or sections, each of which has its own master key (Correct answer)
- A duplicate set of locks kept in emergency storage
Correct answer: Multiple groups or sections, each of which has its own master key
A Grand Master Key operates all locks across multiple sections or groups that each have their own master key, sitting above the master key level.
Question 4: What does 'MACS' stand for in master key system design?
- Master Access Control System
- Maximum Adjacent Cut Specification (Correct answer)
- Multiple Actuator Cylinder Standard
- Master Alignment and Cut Setting
Correct answer: Maximum Adjacent Cut Specification
MACS (Maximum Adjacent Cut Specification) is the maximum allowable difference between adjacent cuts on a key, ensuring reliable operation without binding.
Question 5: Which key occupies the apex of a complex master key system hierarchy and operates every lock in the entire system?
- Sub-master key
- Grand master key
- Top master key (Correct answer)
- Control key
Correct answer: Top master key
The top master key is the highest-level key in a master key hierarchy, capable of operating every lock throughout the entire system.
Question 6: What is a 'sub-master key' in a master key system?
- An emergency copy of the master key stored in a safe
- A key that operates a defined subset of locks within a larger master key group (Correct answer)
- A key used only in basement or sub-level areas
- A reduced-security version of the master key
Correct answer: A key that operates a defined subset of locks within a larger master key group
A sub-master key operates a specific subset of locks within a larger group, sitting between the change key and the master key in the hierarchy.
Question 7: What is the primary purpose of a 'key control' system in a locksmith's security recommendations?
- To prevent unauthorized key duplication (Correct answer)
- To reduce the overall cost of key duplication
- To ensure all keys are color-coded for easy identification
- To standardize key sizes across all locks in a facility
Correct answer: To prevent unauthorized key duplication
Key control systems are designed to prevent unauthorized key duplication, ensuring only authorized personnel can obtain additional keys to a facility.
CRL Master Key Systems & Key Control 1
In a master key system, what is the function of a 'change key'?