Hinge Fabrication Methods

in Hinge History

This modern-day blacksmith is hammering a piece of red-hot iron, much like a Hittite blacksmith might have thousands of years ago. Hinges have come a long way since blacksmiths stood over fiery crucibles to forge them one by one, but the question of how to make a better hinge is one that still hangs over hinge manufacturers today. If you’ve ever wondered why one door hinge can be $3, while a seemingly equivalent door hinge is $75, knowing how hinges are made may help answer your question.
This modern-day blacksmith is hammering a piece of red-hot iron, much like a Hittite blacksmith might have thousands of years ago. [2]
The quality of the base metal will be one of the big factors in hinge prices. Steel, the main product of iron and carbon, is a common base metal for hinges, but can be further altered. Add chromium to the mix and you have stainless steel, which makes your hinge more capable of resisting corrosion, even in salt water.[1] Brass, another popular hinge metal, is copper mixed with zinc; while bronze, the stuff of the most posh hinges, is a mix of copper and tin. Both brass and bronze are much easier to work into hinges than pure copper, and resist corrosion better as well.  [See our history of metal in hinges article for more information.] Commercial facility for smelting and casting copperBusinesses must bring together the four factors of production in order to turn out a product successfully. This copper smelting factory could not function if it were not for the entrepreneur who financed and organized the business, the workers who operate the factory, the raw materials used to produce a final product, and the capital investment in equipment and real estate. [3]
commercial rolls of steel sheet What happens to the metal on its way to becoming a hinge will also be a key price driver. The basic element in turning a lump of ore into a sleek hinge is heat, which these days is usually produced in an industrial size smelter rather than over an open flame. Fired up enough, metals can be forced into new shapes, like plates and sheets, and even new chemical compositions.
Rolls of steel
sheet metal that has been cut, stamped, and finished After heat, hinge-making hinges on machinery. The most basic “production” hinges are stamped out of metal (usually steel or brass) that has been flattened into plates. The resulting hinges are serviceable, but somewhat thin. To mass-produce hinges of a higher-quality, some manufacturers turn to extrusion, or the process of forcing the metal into a die under high pressure. Both hot and cold metals can be extruded, but cold-extruded metals will have a smoother surface. Extruded hinges are thicker and sturdier than stamped hinges, but also more expensive than stamped hinges.
“Sheet Metal” from David Gonzales Photography corporate portfolio
diagram that shows the process of extruding metal; it involves: using force to ram soft metal through a die aht is held in place within a container, dummy block, and die holder Types of Metal fabrication processes [4]Metal fabrication can be divided to forming, removal and non-conventional. 

Metal Forming includes: forging, rolling, extrusion, drawing, deep Drawing, bending, spinning, and turret punching.

Cast and formed metal parts often require further processing or finishing operations to impart specific characteristics such as dimensional accuracy and surface finish. There are several methods of metal removing such as metal cutting, abrasive process and non-conventional metal removing processes.

Metal Removal includes: sawing, shearing, blanking, tapping, broaching, boring, turning, drilling, milling, and grinding.

Non-Conventional fabrication methods include: laser cutting, electro discharge machining, wire-cut EDM, and waterjet cutting.

See more about metal fabrication at the Online Machine Shop.

Some methods are more precise and expensive than others. Some tools are more powerful, precise, and expensive than others. This will affect the cost (and value) of a hinge.

Are the holes drilled well so that each screw has a consistently good fit? Are the edges finished well so that they don’t cause abrasion? Do the parts of the hinge align properly under a reasonable weight load?

The best hinges will be made by a manufacturer that has powerful, precision equipment that is maintained regularly, in addition to having good staff and efficient manufacturing processes. Some of the best manufacturer brands for hinges are: Stanley, Amerock, Blum, and Hager.

diagram that shows the process of shearing metal; includes a die on which the metal rests and a punch (in the desired shape) that forcefully punches into a hole in the die to shear off a metal shape
Some methods of fabricating metal products [4]
Laser cutting of hinges 

The importance of being able to mass-produce hinges can be seen in the success of the Stanley Works, one of the oldest hinge-makers in America today. In making wrought butt hinges, a heavy door hinge, the company beat its rivals in the 1860s with special machines that punched holes in hinges up to 15 times as fast as the others and drove pins into hinges while the others were still doing it by hand. [5]

Stanley ball-bearing butt hinge

Stanley Half Mortise Hinge Template
Template properties for a full mortise hinge from Stanley Works
photo of people pouring metal into a mold, casting metal,  in a commercial setting When you’re looking for a high-end door hinge or cabinet hinge, however, you might look for one in cast bronze. In casting, bronze is melted and poured into a mold, and then finished off by hand so that its surface is perfectly smooth and its pins are perfectly aligned. This helps explain the $75 price tag you might find on a bronze door hinge, compared to the $3 tag on a steel door hinge of the same size.
For door hinges, the quality designations rest largely on the method of production. Stamped hinges would be considered residential grade, while extruded hinges ones could be either residential grade hinges or the higher-quality architectural grade hinges.  Hand-cast bronze door hinges would always be considered architectural grade hinges. (can link to part of website that describes this more)Hinges do wear out, of course. Every time a door slams shut or a chest lid is clamped down, a tiny bit of the hinge metal erodes. One way to mitigate that process is to buy a ball-bearing hinge. These hinges, patented by Stanley Works in 1899, have balls between the joints to make the hinge glide better every time it is set into motion, and are a necessity for heavy doors. Ball-bearing hinges will cost more than plain hinges, but make it easier to shut doors and will last longer since there is less erosion with every swing of the door.  Other factors which help increase hinge life are long hinge knuckles and wider hinge pins, which reduce wear by distributing the weight over a larger area. 

So now that you know where hinges come from, happy hinge-hunting!

- Article by Alix Stuart
Active Lightning Specialist

[1] Iron and Steel from Thor’s Hammer to the Space Shuttle by Ruth G. Kassinger, (Twenty-First Century Books: Brookfield CT, 2003), p.64

[2] Iron and Steel from Thor’s Hammer to the Space Shuttle By Ruth G. Kassinger Published; Material World, Twenty-First Century Books, Brookfield CT; 2003

[3] http://encarta.msn.com/media_461547490/Smelting_Copper.html

[4] eMachineShop.com, http://www.emachineshop.com/machines/metal-fabrication.htm

[5] The Legend of Stanley: 150 Years of The Stanley Works by Jeffrey L. Rodengen, (Write Stuff: Ft. Lauderdale, FL, 1996), p.27-9.

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