Certified Master Locksmith (CML) — Questions and Answers

Question 1: In Certified Master Locksmith, what is the PRIMARY purpose of conducting regular safety drills and exercises?

To reduce daily workload
To satisfy insurance requirements only
To ensure personnel can respond effectively in emergencies (Correct answer)
To evaluate employee performance reviews

Correct answer: To ensure personnel can respond effectively in emergencies

Regular safety drills ensure that all personnel are prepared to respond effectively during actual emergencies.

Question 2: What is the primary purpose of a tamper switch on an alarm system control panel?

To test backup battery capacity
To detect unauthorized opening of the panel enclosure (Correct answer)
To reset the alarm after a trigger
To adjust sensitivity of motion detectors

Correct answer: To detect unauthorized opening of the panel enclosure

Tamper switches generate an alert if the panel enclosure is opened without authorization, protecting the system's brain from physical defeat.

Question 3: In a grand master key system, the hierarchy from highest to lowest access is:

Master key → grand master key → change key
Change key → grand master key → master key
Grand master key → master key → change key (Correct answer)
Change key → master key → grand master key

Correct answer: Grand master key → master key → change key

The grand master key has the broadest access (all locks), master keys operate subgroups, and change keys open only individual locks.

Question 4: Under NEC Article 760, low-voltage fire alarm wiring must be kept separate from which of the following?

Cat6 data cabling
Coaxial cable
120V or higher power wiring (Correct answer)
Telephone wiring

Correct answer: 120V or higher power wiring

NEC 760 requires fire alarm conductors to be physically separated from power-limited and line-voltage electrical wiring to prevent interference and fire hazard.

Question 5: What is a sidewinder (laser-cut) key?

A key with cuts machined into the center channel on both sides of the blade (Correct answer)
A key with serrations on one side only
A key with a built-in transponder chip
A double-sided reversible key

Correct answer: A key with cuts machined into the center channel on both sides of the blade

Sidewinder/laser-cut keys have cuts machined into the center groove (track) running along both sides of the blade, providing higher security than traditional edge-cut keys.

Question 6: What is the correct term for a key designed to operate all vehicles in a company fleet with different key cuts?

Skeleton key
Universal key
Grand master key
Fleet master key (Correct answer)

Correct answer: Fleet master key

A fleet master key is specifically designed to operate all vehicles within a fleet, though modern transponder immobilizers have largely eliminated the use of mechanical fleet masters.

Question 7: Which tool is used to determine a vehicle lock's bitting without removing the cylinder?

An impressioning file
A decoder or tryout key set (Correct answer)
A pick gun
A plug follower

Correct answer: A decoder or tryout key set

Decoder tools and tryout key sets allow a locksmith to read the bitting of an existing lock cylinder without disassembly.

Question 8: What is a key aspect of good business practices?

Quality service and honesty (Correct answer)
Ignoring client feedback
Misleading customers
Overcharging clients

Correct answer: Quality service and honesty

Good business practices are fundamentally built on providing high-quality services that consistently meet or exceed customer expectations, coupled with transparent and honest dealings. This approach fosters strong customer relationships and loyalty, enhancing the business's reputation and ensuring its long-term success. Honesty and quality service are cornerstones of trust.

Question 9: What is the purpose of a key control log?

Discard keys
Ignore key management
Duplicate keys
Track key issuance and return (Correct answer)

Correct answer: Track key issuance and return

The purpose of a key control log is to meticulously track the issuance, return, and current location of all keys within a system. This detailed record helps maintain accountability for each key, identifying who has possession of which key at any given time. A well-maintained log is crucial for security management, preventing unauthorized access, and quickly addressing lost or stolen keys.

Question 10: A vault door's 'swing bolt' design means the bolts:

Are spring-loaded for automatic relocking
Move in a straight linear path when operated
Pivot or rotate into locked position rather than extending linearly (Correct answer)
Can only be operated from the inside

Correct answer: Pivot or rotate into locked position rather than extending linearly

Swing bolts rotate on a pivot point to engage the door frame, which is mechanically stronger against prying than linear bolts in some configurations.

Question 11: What is the standard voltage used for most low-voltage access control locking devices in the US?

48V DC
24V DC or 12V DC (Correct answer)
9V DC
120V AC

Correct answer: 24V DC or 12V DC

Most access control locking hardware operates on 12V DC or 24V DC low-voltage power to comply with safety codes and allow use with standard access control power supplies.

Question 12: When a CML installs an electric strike on a hollow metal door frame, which step is critical to prevent premature failure?

Avoiding any silicone sealant near the strike
Wiring the strike in a normally-open configuration by default
Using only adhesive to secure the strike in the frame cutout
Ensuring the strike is rated for the door's swing direction (LH, RH, LHR, RHR) and properly mounting with the supplied fasteners (Correct answer)

Correct answer: Ensuring the strike is rated for the door's swing direction (LH, RH, LHR, RHR) and properly mounting with the supplied fasteners

Installing an electric strike with the wrong handing or using incorrect fasteners can cause misalignment, mechanical failure, and void the product warranty.

Question 13: When installing a cylindrical lockset, what is the correct relationship between the latch backset and the edge bore?

The backset is measured from the door hinge, not the edge
The edge bore center must be located at the same distance from the door edge as the specified backset (Correct answer)
The edge bore diameter determines the backset automatically
The edge bore must always be 1 inch larger in diameter than the backset measurement

Correct answer: The edge bore center must be located at the same distance from the door edge as the specified backset

The backset is the distance from the door edge to the center of the cross bore, and the edge bore must be centered at that exact distance to ensure proper latch alignment with the strike.

Question 14: What is a transponder in an automotive key system?

A high-security laser-cut key blank
A key with an integrated remote fob
A microchip in the key head that communicates with the vehicle's immobilizer (Correct answer)
A mechanical anti-theft key profile

Correct answer: A microchip in the key head that communicates with the vehicle's immobilizer

A transponder is an electronic chip embedded in the key head that transmits an authorization code to the vehicle's immobilizer to permit starting.

Question 15: What is the function of the control lug on a removable-core (BEST-type) cylinder?

It retracts when the control key is inserted, allowing the core to be removed from the housing (Correct answer)
It engages the cam to operate the locking bolt
It prevents the plug from rotating more than 180 degrees
It locks the core to the housing when a regular key is used

Correct answer: It retracts when the control key is inserted, allowing the core to be removed from the housing

The control lug engages the housing to retain the core; inserting the control key retracts this lug, allowing the core to be pulled out and replaced without tools.

Question 16: What is the primary difference between a fail-safe and a fail-secure electrified lock?

Fail-safe locks are cheaper than fail-secure locks
Fail-safe locks are used outdoors; fail-secure locks are used indoors
Fail-safe locks require a key to open; fail-secure locks do not
Fail-safe locks are unlocked when power is lost; fail-secure locks remain locked when power is lost (Correct answer)

Correct answer: Fail-safe locks are unlocked when power is lost; fail-secure locks remain locked when power is lost

Fail-safe locks release and allow egress when power is cut, while fail-secure locks remain locked during a power outage, maintaining security.

Question 17: In a wafer tumbler lock, what prevents the plug from rotating when the wrong key is inserted?

A sidebar that engages the shell groove
Spring-loaded ball bearings that lock into the plug
Wafers that extend into the shell's slots when not lifted to the correct height (Correct answer)
Driver pins that bridge the shear line

Correct answer: Wafers that extend into the shell's slots when not lifted to the correct height

In wafer locks, each spring-loaded wafer protrudes into a groove in the shell; the correct key lifts all wafers flush with the plug's outer diameter, clearing the shell grooves and allowing rotation.

Question 18: What is the MOST important reason for maintaining equipment maintenance logs in CML practice?

To satisfy insurance requirements only
To assign blame when equipment fails
To track maintenance history, predict failures, and demonstrate compliance (Correct answer)
To justify replacement budgets

Correct answer: To track maintenance history, predict failures, and demonstrate compliance

Maintenance logs track history, predict failures, and demonstrate regulatory compliance.

Question 19: What is the primary purpose of maintaining a key duplication log in a locksmith business?

To calculate employee productivity
To track inventory usage for ordering purposes
To provide an audit trail for security and accountability (Correct answer)
To determine popular key types for marketing

Correct answer: To provide an audit trail for security and accountability

Key duplication logs create accountability and can be essential in resolving disputes or assisting law enforcement.

Question 20: Which door hardware component is responsible for controlling the speed and latching of a door, which can affect the reliability of access-controlled electrified hardware?

The door sweep
The door closer (Correct answer)
The threshold
The hinge

Correct answer: The door closer

An improperly adjusted door closer can cause doors to slam, latch poorly, or fail to close completely, directly affecting whether an electrified latch or maglock engages properly.

Question 21: What documentation does ALOA professional standards require for automotive key origination jobs?

Only the VIN number needs to be documented
A record of the customer's ID, vehicle information, and work performed (Correct answer)
No documentation is required for door lock work
Documentation is only required for transponder key jobs

Correct answer: A record of the customer's ID, vehicle information, and work performed

ALOA professional standards require documenting customer identification, vehicle information, and work performed on all key origination jobs to protect both the locksmith and the customer.

Question 22: When performing a 'key system audit,' a locksmith should first:

Replace all restricted key blanks with standard blanks for cost savings
Install new cylinders in all high-security areas
Rekey all locks that cannot be accounted for
Compare the key control log against the actual issued keys and lock inventory (Correct answer)

Correct answer: Compare the key control log against the actual issued keys and lock inventory

An audit begins by reconciling records — verifying that documented key assignments match physical keys in circulation and locks in the field.

Question 23: A locksmith notices that a commercial door's latch is not catching the strike plate and the door rattles. What hardware component adjustment is FIRST recommended?

Adjust the strike plate position or install a strike plate with a larger opening (Correct answer)
Plane the door edge to move the latch centerline
Replace the latch bolt spring inside the lockset
Replace the entire lockset with a higher-grade unit

Correct answer: Adjust the strike plate position or install a strike plate with a larger opening

Strike plate misalignment is the most common cause of a latch not catching; adjusting the strike plate position or installing a strike with an oversized opening is the standard first-line correction before modifying the door or lockset.

Question 24: Which risk management approach is MOST effective for CML professionals when evaluating potential workplace hazards?

Reactive analysis after incidents occur
Delegating all safety decisions to management
Relying solely on historical accident data
Proactive hazard identification and assessment (Correct answer)

Correct answer: Proactive hazard identification and assessment

Proactive hazard identification and assessment allows professionals to identify and mitigate risks before incidents occur.

Question 25: When a CML professional encounters an unexpected result during a procedure, the FIRST action should be to:

Repeat the procedure immediately
Continue and address it later
Report without preliminary assessment
Stop, assess the situation, and determine whether to proceed or seek guidance (Correct answer)

Correct answer: Stop, assess the situation, and determine whether to proceed or seek guidance

Stopping to assess unexpected results is critical for safety and quality.

Question 26: How does wireless technology benefit security systems?

Increases costs
Requires more wiring
Reduces signal range
Enables flexible installation (Correct answer)

Correct answer: Enables flexible installation

Wireless technology significantly benefits security systems by eliminating the need for extensive wiring, which simplifies and speeds up installation. This flexibility allows sensors and devices to be placed in optimal locations without the constraints of physical cables. It makes installations less intrusive and more adaptable, especially in existing structures or rental properties.

Question 27: What is the purpose of a 'day gate' feature found on some high-security combination locks?

Locks the safe automatically at end of business day
Enables the safe to open with only a partial combination rotation for quick daytime access (Correct answer)
Allows the safe to open during daytime hours only via a timer
Provides a single fixed position where the dial can stop for a day-use bypass

Correct answer: Enables the safe to open with only a partial combination rotation for quick daytime access

A day gate allows authorized users to open the safe with an abbreviated dialing procedure during business hours, while the full combination reactivates after hours.

Question 28: What does 'Wiegand' refer to in access control systems?

A brand of proximity card
A type of electromagnetic lock
A door contact standard
A communication protocol used between card readers and access control panels (Correct answer)

Correct answer: A communication protocol used between card readers and access control panels

Wiegand is a widely-used serial data protocol that transmits card data (typically 26-bit format) from a reader to an access control panel.

Question 29: What is 'tailgating' (also called 'piggybacking') in physical security?

Mounting access control hardware on the door's tail end
Running multiple card readers off one controller
An unauthorized person following an authorized person through an access-controlled door without using their own credential (Correct answer)
Wiring REX sensors in series

Correct answer: An unauthorized person following an authorized person through an access-controlled door without using their own credential

Tailgating is a social engineering vulnerability where an unauthorized individual gains access by following closely behind a credential holder through a secured door.

Question 30: The ALOA Code of Ethics requires members to:

Share master key codes with other ALOA members upon request
Refuse service to customers who have switched locksmiths
Report all competitor pricing to ALOA headquarters
Conduct business honestly and maintain the dignity of the profession (Correct answer)

Correct answer: Conduct business honestly and maintain the dignity of the profession

The ALOA Code of Ethics centers on honesty, professional dignity, and ethical conduct in all business activities.

Question 31: What is the role of monitoring services in security systems?

Create false alarms
Observe alerts and respond (Correct answer)
Delay notifications
Ignore alerts

Correct answer: Observe alerts and respond

Monitoring services provide continuous oversight of a security system, receiving alerts from sensors and alarms 24/7. Upon receiving an alert, trained professionals assess the situation and initiate an appropriate response. This often involves contacting the property owner, dispatching emergency services, or verifying the alarm, ensuring a prompt and effective reaction to potential threats.

Question 32: When servicing a Sergeant & Greenleaf (S&G) three-wheel combination lock, what is the standard method to set a new combination?

Use the change key inserted in the back of the lock to set each wheel's gate position (Correct answer)
Contact S&G for a factory reset code
Replace all three wheels with pre-set wheels
Drill out the existing combination and install a new lock

Correct answer: Use the change key inserted in the back of the lock to set each wheel's gate position

S&G combination locks use a change key inserted through the back or a special procedure to rotate each wheel's gate to the new combination numbers.

Certified Master Locksmith (CML)

The CML is ALOA's highest general locksmithing credential, requiring mastery across 28 elective domains including keying systems, automotive, access control, safe/vault services, and business practices. Candidates must pass 90% of available electives with a 70% score on each.

Questions

35 min

Time Limit

70%

To Pass

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