Inserting the Key:
When you insert the key into the lock, it slides into the cylinder's keyway, which is the slot designed to accept the key.
Aligning the Pins:
Inside the cylinder, there are a series of pins that are made up of two parts: the driver pin and the key pin. Each pin is slightly different in length.
The key pin matches the cuts on the key, while the driver pin rests above the key pin.
The key has a specific pattern of cuts that correspond to the lengths of the pins.
Correct Key Alignment:
When the correct key is inserted, the cuts on the key push the pins to specific heights. The goal is to align the pins with the shear line, the gap between the rotating plug and the stationary cylinder housing.
When the pins are aligned with the shear line, the plug is free to rotate.
Turning the Plug:
Once the pins are properly aligned, the plug inside the cylinder can turn.
Turning the plug rotates the locking mechanism, such as a latch or bolt, allowing the door to open.
Locking the Door:
When the key is removed, the pins fall back into place, blocking the plug from turning and thus locking the door.
Why the Lock Needs a Key:
The key's cuts correspond precisely to the pin lengths, which makes it unique. Only a key with the right pattern of cuts will align the pins correctly and allow the plug to turn.
Without the correct key, the pins remain out of alignment, and the lock cannot be turned, effectively preventing unauthorized access.
Additional Security Features:
Anti-Pick Pins: Some locks are designed with pins that resist picking tools.
Anti-Drill Features: Harder materials are used in the cylinder to prevent drilling.
Key Control Systems: Some locks have unique key profiles or restricted keying systems, making unauthorized key duplication difficult.