Locksmith Lock Mechanisms 2

Question 1

What is the primary function of the shear line in a pin tumbler lock?

Accepted Answer

It separates driver pins from key pins when the correct key is inserted

Answer

The shear line is the gap between the plug and shell where driver pins separate from key pins, allowing the plug to rotate when the correct key lifts all pins to the proper height.

Question 2

A wafer lock differs from a pin tumbler lock primarily because it uses:

Accepted Answer

Flat spring-loaded wafers instead of stacked pin pairs

Answer

Wafer locks use single flat wafers that spring into slots in the shell, unlike pin tumbler locks which use pairs of driver and key pins.

Question 3

In a disc detainer lock, what holds the plug from rotating when no key is inserted?

Accepted Answer

Rotating discs whose slots are misaligned with the sidebar

Answer

Disc detainer locks use rotating disc tumblers with slots; when no key is present, the slots are misaligned and prevent the sidebar from retracting, blocking plug rotation.

Question 4

Which component in a pin tumbler lock provides upward pressure on the driver pins?

Accepted Answer

The bible springs

Answer

Bible springs (pin springs) sit above each driver pin in the shell and push the driver pins downward into the plug, keeping the lock secure without a key.

Question 5

What is 'master keying' achieved by in a standard pin tumbler lock?

Accepted Answer

Adding additional pin stacks with master wafers to create extra shear lines

Answer

Master keying adds master wafers (small spacer pins) between the key pin and driver pin, creating extra shear line positions that multiple keys can use.

Locksmith Practice Test

Locksmith Practice Test

Locksmith Lock Mechanisms 2