CML Keying Systems & Key Control 4 — Questions and Answers
Question 1: What does 'keyed alike' (KA) mean when specified on a lock order?
- All locks in the order use the same keyway but different cuts
- All locks in the order are operated by the same key (Correct answer)
- All locks can be rekeyed to match any existing key
- All locks share a common master key
Correct answer: All locks in the order are operated by the same key
Keyed alike means all locks specified operate with the same key cut combination, commonly used when a customer wants one key to open multiple locks.
Question 2: In a master key system, 'selective master keying' means:
- Only certain locks in the system have master pins installed
- A key is masterkeyed to open specific locks chosen from across different groups (Correct answer)
- The master key is only issued to selected personnel
- Certain keys are cut to work only during specific hours
Correct answer: A key is masterkeyed to open specific locks chosen from across different groups
Selective master keying creates a key that opens a custom combination of locks regardless of their group assignment, used for special access needs.
Question 3: What is the correct procedure when a key is reported lost in a high-security master key system?
- Issue a replacement key and update the log
- Rekey only the locks the lost key could access and update the key control log (Correct answer)
- Rekey the entire facility immediately
- Wait 30 days before taking action in case the key is found
Correct answer: Rekey only the locks the lost key could access and update the key control log
Best practice is to rekey all locks accessible by the lost key to eliminate the security risk, then update the key control log to reflect the change.
Question 4: What is a 'construction master key' (CMK) and what happens to it after construction?
- A key used to open all locks during construction that is voided when occupants move in by turning a key or activating a mechanism (Correct answer)
- A temporary key issued to contractors that expires after 90 days
- A key that opens only exterior doors during the construction phase
- A grand master key held by the general contractor permanently
Correct answer: A key used to open all locks during construction that is voided when occupants move in by turning a key or activating a mechanism
A construction master key allows access during building construction and is voided when the permanent occupant uses their key, which triggers a pin change that disables the CMK.
Question 5: Which standard governs the grading of key control and high-security cylinders in the United States?
- ANSI/BHMA A156.30
- UL 437 (Correct answer)
- ASTM F883
- NFPA 80
Correct answer: UL 437
UL 437 is the Underwriters Laboratories standard that defines requirements for high-security key locks and cylinders, including resistance to picking, drilling, and key control.
Question 6: A locksmith discovers that two different change keys in a master key system can open each other's locks. This condition is called:
- Cross keying
- A phantom key
- A related key (Correct answer)
- A false bitting
Correct answer: A related key
A related key condition occurs when two change keys are so similar in bitting that one can operate the other's lock, representing a serious security flaw in the system design.
Question 7: What is the purpose of a 'key blank cross reference guide' for locksmiths?
- To identify which locks have been compromised by unauthorized keys
- To find equivalent key blanks from different manufacturers that fit the same keyway (Correct answer)
- To document the chain of custody for restricted key blanks
- To calculate the maximum number of keys possible under a master
Correct answer: To find equivalent key blanks from different manufacturers that fit the same keyway
A cross-reference guide allows locksmiths to identify interchangeable key blanks from multiple manufacturers, ensuring the correct blank is used when the original brand is unavailable.
CML Keying Systems & Key Control 4
What does 'keyed alike' (KA) mean when specified on a lock order?