What is a Hinge and How Does It Work?
A door hinge is a mechanical device that allows a door to swing open and closed on a frame. The hinge is typically composed of two metal plates – or leaves – that are joined together by a pin and knuckle.
The knuckle is the cylindrical part of the hinge that connects the two leaves and allows them to rotate around the pin.
The pin is the rod-shaped component that runs through the knuckle and connects the two leaves. The hinge leaves are attached to the door or cabinet frame, allowing the door to pivot on the pins.