A hinge is a mechanical component used to connect the surfaces of two objects. It allows the surface to rotate about a fixed axis, as shown in the adjacent photo. One of the most common applications for hinges is doors. Whether in a home or commercial setting, hinges are commonly used to mount a door into a door frame. The hinge holds the door in place while also allowing it to rotate open and closed.

The butt door hinge installation before determining the type of Interior door hinge is half cover, full cover or internal cover before the implementation of the installation, before the installation of the butt door hinge to determine the minimum margin of the Interior door hinge installation.