How far from the edge of the door is the key cylinder typically located?

The key cylinder in a door is typically located 1-3 inches from the edge of the door. This measurement provides a balance between accessibility for the user and structural integrity of the door. Placing the key cylinder too close to the edge could weaken the door, making it more susceptible to breakage or forced entry. Conversely, if the cylinder is positioned too far from the edge, it could complicate the access and security functions of the door. The standard range of 1-3 inches ensures that the locking mechanism is both practical for everyday use and compatible with common door designs, which is why this answer is accurate.