Common hinge manufacturing processes

Hinges can be manufactured by casting, extrusion, forming, or milling. Each process has its advantages and is chosen based on hinge shape, material, cost, and available technology. Take forming, for example, an inexpensive and straightforward way to mass-produce hinges with acceptable tolerances. But because of its low product strength. If heavy-duty hinges are required, a milling or casting process can be used.

Casting：

Casting is the process of injecting liquid metal into a mold cavity containing the shape of the product. Casting was one of the first metalworking processes used to manufacture hinges. To make a cast hinge, make a replica of the desired shape on a piece of wood, metal, plastic, or plaster. For the barrel, an extra figure is made of sand or metal inside the shape to make it hollow. Next comes the preparation of the mold, a special type of sand that is wrapped in a frame called a flask. Once the sand is filled, the hinge pattern can be removed. When the mold is ready, the molten metal is poured into the cavity and allowed to solidify. Once solidified, the mold breaks, and the sand is removed from the casting. The castings are then cleaned, smoothed and heat treated to enhance their properties.

Extrusion：

Extrusion is a metalworking process (though also applied to plastics) in which metal is forced through a die with the desired cross-section. The resulting shape will have a fixed cross-sectional profile. To create a butt hinge, this extruded metal is then milled, depending on the desired blade length and pitch. The geared continuous hinge, on the other hand, does not require further milling because its section is fixed over the entire length. Aluminum is a common material for extruded hinges. The thickness of the hinge can easily be molded with a thicker hollow section, thus making the hinge stronger.

Forming (Stamping)：

Metal forming of hinges involves the use of forming tools such as rollers and dies to cut and withstand a thin sheet of plastic deformation. Like casting, hot forging metal forming was one of the earliest production methods for metal products. Stamping is a common forming process in which a blank is pressed against a die. The mold is designed so that applying the required pressure will produce exactly the desired shape of the hinge. Stamped hinges have higher dimensional accuracy and can be produced at a lower cost than cast and extruded hinges. Additionally, the hinges are cold worked (for the cold forming process), which means stronger, stiffer gauges are produced in the material. One disadvantage of formed hinges is the limited size of the hinges. The thicker the board, the more difficult it is to form.

Cutting or Milling：

This process involves the use of lathes, shapers, drills, or milling machines to remove excess material from metal workpieces. Milling is a common method for producing hinges of precise dimensions. Milled hinges can be made thicker, similar to casting and extrusion processes.

After the hinge is formed, secondary processing is also required. These secondary processes are a combination of heat treatment, galvanizing, painting, painting, polishing, etc. Heat treatment allows the hinge to obtain the desired mechanical properties such as toughness, strength, and hardness. Galvanizing, coatings, and paints provide corrosion resistance for outdoor environments. Polish, polish, and polish the decorative hinges.