Locksmith Lock Mechanisms 5 — Questions and Answers
Question 1: What is the function of a 'anti-drill plate' in a high-security lock cylinder?
- It prevents the key from wearing down over time
- It is a hardened steel plate positioned to stop or deflect drill bits aimed at the shear line (Correct answer)
- It reinforces the plug against torque attacks
- It prevents the cylinder from being removed with a slide hammer
Correct answer: It is a hardened steel plate positioned to stop or deflect drill bits aimed at the shear line
An anti-drill plate (or hardened steel insert) is strategically placed in front of the pin stacks so that a drill bit contacts the hardened steel rather than the brass tumblers, preventing drilling attacks.
Question 2: What does 'rekeying' a lock involve?
- Replacing the entire lock body with a new one
- Changing the key pins in the cylinder so that a new key operates the lock and old keys no longer work (Correct answer)
- Reprogramming an electronic access code
- Replacing the springs and driver pins only
Correct answer: Changing the key pins in the cylinder so that a new key operates the lock and old keys no longer work
Rekeying involves removing the existing key pins from the plug and inserting new key pins sized to match a new key, rendering previous keys inoperable.
Question 3: A 'euro profile' cylinder (DIN standard) is characterized by:
- A round format designed for American-style door prep
- An oval double-cylinder format common in European mortise locks with standardized dimensions (Correct answer)
- A rim-mount cylinder with a surface-mounted lock case
- A tubular format used exclusively in vending machines
Correct answer: An oval double-cylinder format common in European mortise locks with standardized dimensions
Euro profile cylinders follow DIN 18252 standards and have a double-oval shape that fits European-style mortise lock cases, with standardized dimensions for interchangeability.
Question 4: In a pin tumbler lock, what is a 'top pin' also commonly called?
- Key pin
- Driver pin (Correct answer)
- Master wafer
- Follower pin
Correct answer: Driver pin
The 'top pin' or 'driver pin' is the upper pin in each stack that is pushed down by the spring and must be lifted above the shear line by the correct key for the lock to open.
Question 5: What is the purpose of the 'follower' tool used by locksmiths when removing a cylinder plug?
- To apply rotational torque to the plug during picking
- To push into the plug hole after the plug is removed so that driver pins and springs do not fall out of the shell (Correct answer)
- To hold the key in position while rekeying
- To measure pin heights during duplication
Correct answer: To push into the plug hole after the plug is removed so that driver pins and springs do not fall out of the shell
A plug follower is inserted into the shell as the plug slides out, keeping all driver pins and springs contained in their chambers so they can be reinserted correctly during rekeying.
Question 6: Which lock mechanism type is specifically designed so that the key can only be removed in the locked position?
- Spring latch mechanism
- Deadbolt with key-retaining feature
- Interchangeable core mechanism
- Key-retaining cylinder (hotel/motel function) (Correct answer)
Correct answer: Key-retaining cylinder (hotel/motel function)
Key-retaining cylinders (often used in hotel or institutional functions) are engineered so the key cannot be withdrawn until the lock is fully rotated to the locked position, ensuring doors are never left unlocked.
Question 7: What is the 'plug' in a pin tumbler cylinder lock?
- The external housing that contains all other components
- The rotating inner cylinder that accepts the key and turns to operate the lock mechanism (Correct answer)
- The metal plate that covers the lock face on the door
- The spring assembly that returns the bolt after operation
Correct answer: The rotating inner cylinder that accepts the key and turns to operate the lock mechanism
The plug is the inner cylindrical core of the lock that the key is inserted into; when the correct key lifts all pins to the shear line, the plug rotates within the shell to operate the lock.
Locksmith Lock Mechanisms 5
What is the function of a 'anti-drill plate' in a high-security lock cylinder?