Hinges have been in existence for a very long time. Early hinges were made of straps of leather or cloth. These materials broke easily and provided an inexact point of closure. Later, hinges were forged in iron or brass and mounted close to the pivot point for more strength and precision closure.
Early Desk Hinges
One of the earliest desk hinges used was the barrel hinge. In this model, two interlocking metal leaves would wrap around a single pivot point. The material of choice was wrought iron. A skilled iron worker could forge, cut and hammer iron into any shape. The molten mineral fibres found in wrought iron made it extremely durable and surprisingly rust resistant. Early iron hinges were mounted on the desk lid surface and casework in H, T and butterfly shapes. Numerous nails, partially hammered and then bent over, held hinges in place until the advent of screws in the 18th century.
During the 17th century, the use of brass came into favour. Furniture was more refined and less rustic. Brass had a more delicate and artistic look than the older forged iron. As an alloy of copper and zinc, brass was easily cast, cut and polished. Until the 20th century, cast brass was used. Later, pressed brass was adopted because it was cheaper to form. Today's higher quality desk hinges use stronger, longer-lasting hinges made of extruded brass.
Inset or Overlay
In traditional furniture, the desk hinge was inset so the desk lid or door could sit flush with the cabinetry. Hinges were a desk component to be hidden, not featured in desks of the 18th and 19th centuries when furniture design and the beauty of the wood were of paramount importance. Only the front half of the barrel hinge could be seen because hinges were inset into the edges of the lid or door and the inside edge of the casework. Plain butt hinges would be stained with the wood to further blend in.
The swaged hinge is traditionally American in style. Most early 29th century American manufacturers formed hinges from sheet metal. For economy, the flat part of the hinge (leaf) was made of thinner metal, while the barrel or knuckle, through which the pin passed, was enlarged to increase bearing capacity. Swaging is "the forming of one or both leaves toward or beyond the centre of the pin," according to Hoffman Hinge and Hardware. Swaging slightly increased the width of the leaf. A swaged hinge is a hallmark of the American-made desk.
Flatback, or standard assembly, hinges originated in England in the early 18th century. English brass butt hinges were sand cast and hand-fitted, making them very brittle if not cut thickly. Each hinge leaf was cut to a thickness of almost half the diameter of the hinge barrel. Many English butt hinges were tapered from the barrel outward to save material and enhance the look. This was possible because the greatest stress occurred near the barrel, so no strength was sacrificed by the design.