A continuous hinge is a long hinge with a wide range of movement typically used in cabinet and furniture making. Also known as a piano hinge, the continuous hinge is generally used as a single unit, spanning the entire length of the hinged area of a door or lid. The hinges are supplied in long lengths that may be cut to size and are typically pre-drilled with equally-spaced holes along each wing. In most cases, the continuous hinge is constructed of light-gauge metal with a fairly light knuckle-and-pin section in relation to the wings, with heavy-duty examples available when required. The hinges are also available in a selection of plastic materials suitable for epoxy attachment rather than screws or rivets.
The continuous hinge was initially developed to provide the hinged joint in piano lids, hence its alternate name. To achieve a sturdy yet unobtrusive joint in this application, the hinge was designed to be light with a small central pin and knuckles that allowed the piano lid to close with a very small hinge gap or to open all the way back without spoiling the appearance of the cabinetry. To ensure that the hinge provided sufficient strength for the often heavy lids, it was designed to span the entire length of the lid, secured at regular intervals with wood screws. The hinge was eventually adopted by cabinet and furniture makers for a wide variety of low-profile applications.
Generally available in extended lengths, even being presented on a roll at times, the continuous hinge is made from light-gauge, plated steel with wide wings in relation to a relatively small pin-and-knuckle section. In most cases, the hinge's pin is little more than a heavy-gauge wire core running along its entire length. When a hinge is needed, the required length is measured and cut off with a hacksaw. The hinge is generally pre-drilled with a series of equally-spaced holes along each wing. The holes are generally close together so, during installation, the number of screws or rivets used can be adjusted to suit the application.
The small knuckle section of the continuous hinge allows for an excellent range of motion as well as subtle joint gaps. They are also available in heavy-duty guise, though, should the need arise. A selection of lightweight plastic or acrylic continuous hinges are also available in a wide range of colors. These hinges are often not pre-drilled for screw or rivet attachment, but rather designed for use with acrylic adhesives.