Something about the door hinges
2008-08-20

A hinge is a type of bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation (the geometrical axis of the hinge). Hinges may be made of flexible material or of moving components. In biology, many joints function as hinges. They are also known as shingles in old tutorial English (the large hinges on doors). Hinge-like structures are employed in many types of movable bridges. Hinges today come in all shapes, sizes and finishes, but chances are they have one thing in common: they’re made of metal. As to the door hinges, there are a long history to talk about. It is also developed as the steel existence. Let me have a look.  

         Steel is a favorite for hinges of all types. It is relatively cheap, strong, and durable. Its evolution from outcast to ordinary, however, is anything but common. Early civilizations initially eschewed iron, the basic component of steel, since it requires extremely high temperatures (2800 F) to melt in its pure form. 

          Not until the second millennium BC, around 1400 BC, did the clever Hittites find a way to adequately heat iron so that it could be pounded into swords and other tools. Soon after, they apparently also discovered steel, an alloy of iron and carbon that is even stronger and potentially sharper than iron alone. Legend has it that the first steel formed when, in the heating and pounding process, blacksmiths left the swords-to-be on the charcoal a bit too long and some of the charcoal’s carbon fused into the iron. The effect would have been dramatic: under the right conditions, steeled iron can be twice as strong as bronze, the previous metal of choice.

         The production of steel in modern times took off with the invention of the steam engine to power factories, and in particular after 1856, when British engineer Henry Bessemer discovered a process to make steel in one-twentieth of the time it had previously taken.There are many steel alloys, but one in particular bears notice when it comes to hinges: stainless steel. This steel is composed of at least 10.5 chromium, which reacts with oxygen in the air to form a very thin film of chromium oxide on the surface of the steel. This oxide becomes a protective layer, preventing the steel inside from reacting to any other elements, and regenerating itself if damaged.[5] The discovery of this corrosion-proof metal is generally credited to a Brit named Harry Brearley, who chanced upon it while trying to find an erosion-proof metal for a gun manufacturer in the early 1900s, though many including the Krupp Company in Germany have further developed it over the ages. The main benefit of stainless steel in hinges is that the metal won’t rust, even when exposed to salt water and salt air, where a steel hinge alone would begin to rust within a year. This makes the metal ideal for boat hinges, or door hinges for your beachfront property. For all its benefits, however, steel has some drawbacks as a hinge base when compared to brass and bronze. Stainless steel hinges are usually not aesthetic enough for general use, since they don’t take finishes. The way most other steel hinges are manufactured today, they are prone to corrosion. Painting steel can help make it last longer in a hinge. But when it comes to hinge finishes, popular ones like oil-rubbed bronze often look better on brass hinges or bronze hinges than on steel hinges. So when you’re looking for a higher-quality hinge to spiff up your front door or add elegance to cabinets, you’re most likely looking for a brass hinge or bronze hinge, which will stand up better to weather and time than a steel hinge.  

        Both brass and bronze are alloys of copper, which is one of the very first metals humans were able to master. Archaeological evidence suggests that people were fashioning copper tools and decorations as far back as 4000 BC, although there is still some mystery as to how they were able to sufficiently heat the copper ore, which has a 1984 F melting point.[7] This high melting point – and a tendency to bubble and oxidize – made copper difficult to work with on its own.  

          Around 3000 BC, however, Near Eastern coppersmiths began mixing copper with tin, creating the very first bronze. Bronze flowed more easily at lower temperatures, did not bubble, and in fact became even harder than copper when cooled.[8] The metal became important enough to have an era named after it: The Bronze Age. Today, bronze is used in the highest-grade hinges, usually still poured into molds and finished off by hand rather than mass-produced. Brass, a mix of copper and zinc, was known to early civilizations, but did not enjoy the popularity of its bronze cousin largely because it was more difficult to produce. The Romans used it to a limited extent in coins and jewelry, but brass was not widely used until about the seventeenth century, when European wool makers used brass pins in weaving. The corrosion-resistance that brass offers also made it an ideal material for clocks and navigational aids used at sea.

      Brass has become even more popular since technology to reliably mass-produce it was introduced in the nineteenth century. These days, brass can offer a big upgrade over steel when it comes to hinges. Brass is typically used inside, for cabinet hinges and interior door hinges, though it could also be used for a front door hinge. Brass hinges are generally thicker than steel hinges, will wear better and look more polished as well.  

        Of course, the look of a hinge can also be affected by the finish you choose for it. While the thin film of finish won’t affect the durability of the base metal, they can help steel, brass, or bronze hinges take on polished, bright, or satin tones. Some finishes mimic the look of ones that originally had some practical use, like the bright shiny effect of chrome. Car manufacturers began to use chrome, or chromium plating, on the steel of car exteriors in the 1920s to help prevent corrosion, but since then it has become a decorative accent for many types of hardware, including hinges.[10] Finishes can also help hinges look like metals which are typically not suitable as a base metal for hinges, such as nickel. Nickel, a silvery metal, is rarely used in pure form. In fact, nickel was not even discovered to be a distinct element until 1751, when Axel Fredrik Cronstedt of Sweden accidentally extracted pure nickel, instead of copper, from the mineral nicotine. Alloyed with copper and zinc, though, nickel has apparently been in use since about 235 BC, as found in early Chinese utensils and tools. Even the U.S. coin known as the nickel is only 25 percent nickel, with the balance being copper. Today nickel is one of the common components of stainless steel, and is often used to coat other metals, since it helps increase resistance to corrosion.  

    So we can see the development of the door hinges. It’s so long but very wonderful. In today’s market, there are many kinds of door hinges. Main types include:

1. Pivot Hinges, which pivot in openings in the floor and the top of the door frame. It is also referred to as a double-acting floor hinge. This type is found already in ancient dry stone buildings. 

2. Butt/Mortise Hinges, usually in threes or fours, which are inset (mortised) into the door and frame. Most residential hinges found in the U.S. are made of steel, although mortise hinges for out swing doors are often made of brass or stainless steel base to prevent corrosion. Butt hinges(standard) vary in size from 1 inch (25mm) up to about 8 inches (200mm), however the most common sizes are 2 ½ inch (64mm), 3 inch (75mm) and 4 inch (100mm). A hinge is measured or described by its height, which usually refers to the length of the joint knuckle.

 3. Continuous Hinges, which run the entire length of the door (also known as "Piano Hinges") Concealed Hinges used for furniture doors (with or without self-closing feature, and with or without dampening systems). They are made of 2 parts: One part is the hinge cup and the arm; the other part is the mounting plate.

4. Butterfly or Parliament (UK) Hinges. These were known as Dovetail hinges from the 17th century onwards and can be found on old desks and cabinets from about 1670 until the 18th century. Parliament hinges get their name from a parliament door which is one that folds 180 degrees back on it. The form of these hinges varied slightly between manufacturers, and their size ranged from the very large for heavy doors to the tiniest decorative hinge for use on jewelers’ caskets. Many hinges of this type were exported to America to support the home trade's limited supply. They are still found to be both fairly cheap and decorative, especially on small items.

5. Strap hinge - Strap hinges are an early hinge and used on many kinds of interior and exterior doors and cabinets. 

6. H Hinges - Shaped like an H and used on flush mounted doors. Small H hinges (3" to 4") tend to be used for cabinets hinges, while larger hinges (6" to 7") are for passage doors or closet doors. 

7. HL Hinges - Large HL hinges were common for passage doors, room doors and closet doors in the 17th, 18th and even 19th centuries. On taller doors H hinges were occasionally used in the middle along with the HL hinges. 

Other types include: • Counterflap Hinge • Flush Hinge • Coach Hinge • Rising Butt Hinge • Double action spring hinge • Tee Hinge • Friction Hinge • Security Hinge • Cranked or 'Stormproof' Hinge • Lift-off Hinges • Self closing Hinges: Butt hinges(standard) vary in size from 1 inch (25mm) up to about 8 inches (200mm), however the most common sizes are 2 ½ inch (64mm), 3 inch (75mm) and 4 inch (100mm). A hinge is measured or described by its height, which usually refers to the length of the joint knuckle. If this is followed by another size, this will refer to the width of the hinge when laid open.  

       We can say it has so many kinds. In fact, hinges play a very important role in our daily life. Different types of hinges come in various sizes; in the very small sizes they would be used on cabinet doors. In selecting any hinge for a door, or selecting glass hinges for glass doors, there is a variety of data one should know: door thickness, weight, and clearance. But a long-time engineering trick makes it simpler: If the hinge seems to be in proportion to the door it's going on, use it. For example, if you are hanging an exterior door, you won't use tiny hinges, nor would you use extra large ones. Door hinges are not all the same. Some old homes have hinges that are ornate, and have square corners. Many modern door hinges are unattractive.   

       So in my opinion, how to do a attractive is the key work for the manufactures. You can replace modern ugly door hinges with gorgeous hinges that are solid brass, look old and have decorative tips. As quality of motion is quality of life, we need hard work.