Locksmith Lock Mechanisms 4 — Questions and Answers
Question 1: A 'deadbolt' lock mechanism differs from a 'spring latch' mechanism primarily because:
- A deadbolt uses wafer tumblers while a spring latch uses pin tumblers
- A deadbolt requires deliberate key or thumb-turn actuation and does not retract under pressure (Correct answer)
- A deadbolt automatically engages when the door closes
- A deadbolt can only be operated from the exterior side
Correct answer: A deadbolt requires deliberate key or thumb-turn actuation and does not retract under pressure
A deadbolt has a square-ended bolt that must be manually actuated by a key or thumb-turn and cannot be pushed back by pressure, unlike a beveled spring latch that retracts automatically.
Question 2: In a double-cylinder deadbolt, what is a major safety consideration?
- It requires two separate keys cut to different bittings
- It requires a key to operate from both sides, which can impede emergency egress (Correct answer)
- It automatically deadlocks after 30 seconds
- It cannot be rekeyed without replacing the entire lock body
Correct answer: It requires a key to operate from both sides, which can impede emergency egress
Double-cylinder deadbolts require a key on both sides, meaning occupants cannot quickly exit in an emergency if the key is not immediately accessible, which is a fire safety concern.
Question 3: What is the role of the 'cam' in a cylinder lock?
- It holds the plug in position inside the shell
- It translates the rotational movement of the plug into the linear or rotational motion needed to operate the lock mechanism (Correct answer)
- It prevents the key from being over-inserted into the keyway
- It applies spring pressure to the driver pins
Correct answer: It translates the rotational movement of the plug into the linear or rotational motion needed to operate the lock mechanism
The cam is attached to the back of the plug and converts the plug's rotation into the motion required to retract a bolt, operate a latch, or drive another mechanism.
Question 4: Which type of lock mechanism uses a rotating curtain to block the keyway when no key is inserted?
- Lever tumbler lock
- Pin tumbler lock with security pins
- High-security cylinder with anti-pick curtain (Correct answer)
- Magnetic lock mechanism
Correct answer: High-security cylinder with anti-pick curtain
Some high-security cylinders incorporate a rotating curtain (or slider) in the keyway that blocks picking tools and must be pushed aside by the correct key profile before tumblers can be accessed.
Question 5: A 'knob lock' mechanism is considered less secure than a deadbolt primarily because:
- It uses fewer pin tumblers in the cylinder
- The locking mechanism is housed in the knob itself and can be defeated by forcibly breaking or wrapping the knob (Correct answer)
- It cannot be rekeyed without full replacement
- It uses wafers instead of pins, which are easier to pick
Correct answer: The locking mechanism is housed in the knob itself and can be defeated by forcibly breaking or wrapping the knob
Knob locks have the cylinder and mechanism inside the knob, making them vulnerable to being snapped or gripped with channel-lock pliers to expose the spindle and retract the latch.
Question 6: What is a 'schlage B-series' deadbolt's most notable mechanical security feature compared to a standard deadbolt?
- It uses disc detainer tumblers for pick resistance
- It includes a reinforced strike plate and anti-saw bolt pin as standard features (Correct answer)
- It uses a tubular key for added key control
- It has a built-in alarm that activates on forced entry attempts
Correct answer: It includes a reinforced strike plate and anti-saw bolt pin as standard features
Schlage B-series deadbolts incorporate an ANSI Grade 1 rating, a hardened steel anti-saw pin inside the bolt, and are typically sold with a reinforced strike plate for improved kick-in resistance.
Question 7: In a lock mechanism, what is 'key control' referring to?
- The torque limit before a key breaks in the cylinder
- The ability to restrict unauthorized duplication of keys for that lock system (Correct answer)
- The number of key cuts required to operate the lock
- The spring force required to operate the lock with the key
Correct answer: The ability to restrict unauthorized duplication of keys for that lock system
Key control refers to the measures—such as patented keyways, restricted blanks, or electronic tracking—that prevent unauthorized copying of keys to a lock or system.
Locksmith Lock Mechanisms 4
A 'deadbolt' lock mechanism differs from a 'spring latch' mechanism primarily because: