A key works in a lock by aligning internal components, called pins, to allow the lock to open. Here's a breakdown of the process:
The common pin tumbler lock uses a set of pins that prevent the lock from turning unless the correct key is inserted. These pins are divided into two or more sections.
| Component | Description |
|---|---|
| Pins | Divided into sections; prevent turning without the key. |
| Key | Has notches that correspond to the pin heights. |
| Cylinder | The part that turns to open the lock. |
| Housing | Surrounds the cylinder. |
| Shear Line | The meeting point between the cylinder and housing. |
Here's how the key interacts with the pins:
- Key Insertion: When you insert the correct key into the lock, the notches in the key push each pin pair.
- Pin Alignment: The correct key will push each pin pair up just enough so that the point where the two pins come together lines up perfectly with the space where the cylinder and the housing come together -- this point is called the shear line.
- Shear Line Engagement: When all the pin pairs are aligned at the shear line, the cylinder is free to turn.
- Lock Operation: Turning the cylinder retracts the bolt, opening the lock.
In essence, the right combination of pins lines up perfectly with the notches in the key, allowing the lock to function.
