Lock Mechanisms & Hardware Flashcards

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

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.

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

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.

A Grade 1 commercial lockset, per ANSI/BHMA standards, is rated for a minimum of how many cycles?

Answer: 500,000 cycles

ANSI/BHMA Grade 1 is the highest commercial grade and requires the lockset to withstand a minimum of 500,000 operational cycles.

What is the main mechanical difference between a mortise lock and a cylindrical (bored) lockset?

Answer: A mortise lock is a complete locking mechanism housed in a rectangular case mortised into the door edge, while a cylindrical lockset's components mount through bored holes

A mortise lock body is a self-contained unit inserted into a pocket (mortise) cut into the door edge, whereas a cylindrical lockset is installed through drilled holes in the door face and edge.

What does the term 'key cut depth' refer to in key specifications?

Answer: The vertical distance from the key's shoulder to the lowest point of a given cut

Key cut depth is the vertical measurement from the key's reference line (shoulder or tip) to the bottom of each individual cut, determining how far each pin is lifted.

Which type of lock cylinder is most commonly found in a standard residential knob or lever lockset?

Answer: Cylindrical (key-in-knob) cylinder

Cylindrical (key-in-knob or key-in-lever) cylinders are specifically designed to fit inside the rotating knob or lever housing of bored locksets and are the most common residential cylinder type.

In a pin tumbler lock, what is the 'bible'?

Answer: The portion of the lock housing containing the pin chambers above the plug

The 'bible' is the colloquial term for the upper portion of the lock shell or housing that contains the driver pin chambers and springs above the plug.