Types of copper

How many different types of copper are there? The material has many applications, and can be used in everything from roofing to candlesticks. Let’s look at the history of copper, how it can be used, and where it comes from! 

The History of Copper

Copper was first used by man over 10,000 years ago. A copper pendant discovered in what is now northern Iraq has been dated about 8700 B.C. For nearly five millennia copper was the only metal known to man, and thus had all the metal applications. Early copper artifacts, first decorative, then utilitarian, were undoubtedly hammered out from “native copper,” pure copper found in conjunction with copper-bearing ores in a few places around the world. By 5000 BC, the dawn of metallurgy had arrived, as evidence exists of the smelting of simple copper oxide ores such as malachite and azurite.

Not until about 4000 BC did gold appear on the scene as man’s second metal. By 3000 B.C., silver and lead were being used and the alloying of copper had begun, first with arsenic and then with tin. For many centuries, bronze reigned supreme, being used for plows, tools of all kinds, weapons, armor, and decorative objects. Though copper came from the island of Cyprus-from whence its name-and numerous other sites in the Middle East, the origin of the tin in the bronze is still a mystery. The Bronze Age suddenly ended at about 1200 BC, with the general collapse of the ancient world and the interruption of international trade routes. The supply of tin in particular dried up and the Iron Age was ushered in, not because iron was a superior material, but because it was widely available. The deliberate alloying of iron with carbon to form the first steels did not occur for centuries. Economy in the use of copper and its alloys was necessitated by these early trade interruptions, and this efficiency in use and re-use has continued from that day to this. While the development of iron smelting put an end to the Bronze Age, the use of copper and bronze did not stop. In fact, the Romans expanded their uses for, and extraction of, copper. The Romans’ engineering ability led to new systematic extraction methods that particularly focused on gold, silver, copper, tin, and lead.

Pure copper suffers from its softness, making it ineffective as a weapon and tool. But early metallurgy experimentation by the Mesopotamians resulted in a solution to this problem: bronze. An alloy of copper and tin, bronze was not only harder but could also be treated by forging (shaping and hardening through hammering) and casting (poured and molded as a liquid).The ability to extract copper from ore bodies was well-developed by 3000 BCE and critical to the growing use of copper and copper alloys. Lake Van, in present-day Armenia, was the most likely source of copper ore for Mesopotamian metalsmiths, who used the metal to produce pots, trays, saucers, and drinking vessels. Tools made of bronze and other copper alloys, including chisels, razors, harpoons, arrows, and spearheads, have been discovered that date to the third millennium BCE.

Where does Copper come From? 

Copper is mined mostly in open pit mines, such as those found in Utah, New Mexico, and Chile. Chile produces the largest percentage of the world’s copper with nearly 33% of the world’s export. Copper is also found in the U.S., Indonesia, and Peru. Ore is first mined, then put through a series of processes to refine and purify the copper.

Copper, a soft red-coloured metal, was one of the first metals to be used in the ancient world. It has been exploited for at least 7000 years. The name comes from the Greek word Kyprios, the name of the island of Cyprus in the Mediterranean Sea where copper occurs. The Latin, cuprum, (Cu) also means “Metal of Cyprus,” as the Romans had large copper mines on the island. Copper is an excellent conductor of heat and electricity and is found in most of the flexible cables used in the world. Its softness also makes it suitable for tubing for water pipes and central heating systems because it can be easily bent to fit around corners. Above all, it can be mixed with other metals to make extremely useful alloys such as brass and bronze.

Copper is a metal that has been deposited from hot sulphur solutions, created in volcanic regions. The hot solutions concentrated the copper up to a thousand times more than would normally be found in rocks. The resultant enriched rocks are called copper ores. The amount of copper in the ground is relatively small and most of it occurs in low-grade ores that have to be processed twice to extract the copper. This is why it is important to reuse as much copper as possible, and why about one-third of copper consumed in most industrial countries is recycled from scrap.

The Different Types of Copper 

1. Piping

Copper pipes are commonly used in the construction industry for water supply lines and refrigerant lines in HVAC (heating, cooling, and air-conditioning) systems. Copper pipes can be manufactured as soft or rigid copper and offer excellent corrosion-resistance and reliable connections. The three most common types of copper pipe used in residential and commercial construction are Type K, Type L, and Type M. A fourth type, used for drain-waste-vent, or DWV, piping, can be found in some older homes.

1. 1. Type K Copper Pipe: Type K copper pipe has the thickest wall of all the common types. It is used for water distribution, fire protection, oil, HVAC, and many other applications in the construction industry. Type K pipe is available in a rigid and flexible form and can be used with flared and compression fittings. It is recommended for main water lines and underground installations because its thickness helps it withstand the pressure from backfilled earth in trenches.
   2. Type L Copper Pipe: Type L copper pipe is used for interior plumbing, fire protection, and some HVAC applications. It is available in rigid and flexible forms and can be used with sweat, compression, and flare fittings. Type L is considered the most common type of copper piping, as it can be used in many more applications than Type K. Flexible Type L copper can be used to repair or replace old water lines, although rigid tubing is more durable. Type L also can be used outside the home where it will be directly exposed. Type L copper is thinner than Type K but thicker than type M.
   3. Type M Copper Pipe: Type M copper pipe is thinner than both type K and L copper pipe. Sold in both rigid and flexible forms, Type M is used most commonly for heating water services and vacuum systems. It can be used with sweat, compression, and flare fittings. Type M tubing is favored for residential work for its relatively low price; a thinner wall means less copper and thus a lower price. Type M copper is not always allowed by plumbing codes in all areas and applications. Always check with the local building authority for restrictions on its use.
   4. Copper DWV Piping: Copper pipe for plumbing drains and vents was used in many old homes and commercial applications and has been all but replaced with PVC or ABS plastic pipe in modern construction. (For specific applications or uses, check your local code.) It is suitable only for above-ground applications and has a low-pressure rating, typically lower than the water pressure of most municipal water supply systems. DWV pipe usually has yellow markings to distinguish it from M type copper. ​

2. Roofing 

Copper offers a character and durability that no other metal roof can match. Its appearance can complement any style of building, from the traditional to the modern. Its warmth and beauty make it a preferred material for many architects.The use of copper is based upon traditional practices proven over many years. There are numerous examples of copper roofs which have been in place one or more centuries. Copper’s resistance to the elements ranks among the highest of modern roofing materials.When properly designed and installed, a copper roof provides an economical, long-term roofing solution. Its low life cycle costs are attributable to the low maintenance, long life and salvage value of copper. Unlike many other metal roofing materials, copper requires no painting or finishing.

Through its natural weathering process, the warm bronze tones can be expected to lead to the elegant green patina finish. There are also a number of methods available to retard or accelerate the weathering process. The ductility and malleability of copper make it an easy material to form over irregular roof structures. Domes and other curved roof shapes are readily handled with copper. In recent years, new tools and installation methods have been introduced that aid in the quick, proper, and economical installation of copper roofs. There are so many famous buildings around the world that use copper for their roofs: The Rotunda is a stunning building designed by Thomas Jefferson to represent the ‘authority of nature and power of reason’. The building’s structure was inspired by the Pantheon in Rome, with a large 77ft domed copper roof and pillars outside. Located on the campus of the University of Virginia, the Rotunda is used as a symbol of Jefferson’s constant dedication to education and architecture. Copper roofs, with that classic mint green finish that results over time, are also very popular in Canada and all over Europe. The Belvedere Palace in Vienna is another example: This magnificent palace is made all the more unique due to its eye-catching green copper roof. The history books claim that the goal of the architect was to create a roof that closely resembled the tents of the Ottoman army. 

3. Art

The usefulness of copper in metalwork is known to all, but few people realize how much it has contributed to art and painting throughout history. Copper-based pigments were an important ingredient in ancient paints, and the metal itself was frequently employed as a “canvas” on which Renaissance artists painted. Copper also served as an engraving plate for etchings and prints by master artists such as Rembrandt. As an ingredient in paint, natural copper ores such as azurite (blue) and malachite (green), add a depth and dimensionality to paintings that cannot be duplicated by man-made substitutes. As for copper’s use as a canvas, there was virtually nothing else available to artists in pre-technological times that approached its smoothness and durability. Around the time of the U.S. Revolution paint pigments were generally not available. Some people made a greenish pigment by suspending copper metal in a container over a pool of vinegar. This would result in a patina or copper salt to form on the surface of the copper which could then be scraped off and used, ground up, and used in paint to produce a paint color we call verdigris. In addition, beginning in the early 16th century, European artists often painted on sheets of copper. Those artists include some of the most famous painters of all time: Leonardo da Vinci, Jan Brueghel, El Greco and Rembrandt. They found that copper provided a smooth, durable surface that held the paint very well and allowed for marvelous effects.

The Statue of Liberty, whilst not strictly a building, is one of the most recognisable statues in the world. Bartholdi, the designer and architect of the structure, decided to use copper sheets to form the statue as it would provide a lightweight material for the figure’s volume. The statue arrived in New York in the 1880s as a gleaming copper icon, but has long since taken on copper’s distinctive green patina that we see today. The Statue of Liberty contains 160,000 pounds of copper. It came from the Visnes copper mines on Karmoy Island near Stavanger, Norway, and was fabricated by French artisans. The Lady’s pure copper sheets are 3/32-inch thick. Her natural, green patina is about 0.005-inches thick and has protected her from corrosion since 1886. A showcase motorcycle named “Spirit of Liberty,” better known as the “Copper Chopper,” was built from scrap metal removed from the Statue of Liberty during the restoration for its centennial in 1986. Contemporary artist David Novros is a good example of a modern-day artist who prefers the medium of copper sheets. He has a series of seven paintings on copper panels as large as 9×6 feet. His work has been shown at the Metropolitan Museum of Art and Museum of Modern Artin New York. “Copper is one of the most malleable metals; pigment bonds well to it, and I like its reflective nature,” Novros explains. “Copper has a historical connection and was considered valuable, like gold and silver.”

By the second millennium BCE, bronze items were also being produced in large quantities in areas of China. Bronze castings found in and around what are now the provinces of Henan and Shaanxi are considered to be the earliest use of the metal in China, although some copper and bronze artifacts used by the Majiayao in eastern Gansu, eastern Qinghai, and northern Sichuan provinces have been dated as early as 3000 BCE. The Egyptians also used copper and bronze for mirrors, razors, instruments, weights, and balances, as well as the obelisks and adornments on temples. Lacking modern knowledge of metallurgy, early societies, including the Mesopotamians, Egyptians, and Indigenous peoples in America, prized the metal mostly for its aesthetic qualities, using it like gold and silver for producing decorative items and ornaments. It continues to be used for artistic purposes, as well as practical ones. 

4. Wiring

Copper is the popular choice for many wiring applications, mainly because of its durability and high conductivity. However, it is not without its faults. Apart from its higher cost, it’s also heavier, which means it requires the construction of more structural support. This, in turn, means a bigger investment on your part. To get an electrical current to flow through metals, the power source has to fight against resistivity. The lower the level of resistivity, the more electrical conductivity a metal has. And since copper wire has a low level of resistivity, it’s a fantastic electrical conductor. Copper is also an incredibly flexible material. Electrical connectors and wiring need to handle large loads of electricity at a time, but most metals that take on these loads don’t bend easily. Copper, on the other hand, has the ideal level of thickness to handle household levels of electricity, while still being maneuverable. Lastly, copper is less oxidative than other metals. You’ve likely heard of oxidation when talking about rust. It happens when the oxygen and moisture in the air react with a metal’s surface. This reaction corrodes the metal which makes a film-like covering. Copper doesn’t rust but it will produce a greenish patina called copper oxide. Unlike rust, however, this coating protects the metal from corroding without interfering with the conductivity.

5. Health and Wellness

Copper is an essential mineral for bone strength, heart health, immune health, and much more. Your body needs a small amount of it to function properly. But because your body can’t make copper on its own, you have to get it through your diet. Therefore, there are many companies that make copper supplements. You may have seen that some people wear copper gloves, bracelets, and other copper items. It’s not just because they look nice. Since ancient times, copper has been used as a folk remedy for sterilizing wounds, fighting infection, and treating inflammation. Advocates of copper jewelry use in the modern era believe copper has healing properties. It can be absorbed by the skin, perhaps to treat or even prevent arthritis and other inflammatory diseases. However, scientific research has yet to back up these claims. Studies done in volunteers who have arthritis have shown no benefit from wearing copper jewelry. The as-yet limited research has yielded some evidence to support their use in medicine, but even more studies have emerged advising that they have no clinical impact.

Copper is also found naturally on the skin. Copper has been used in the skincare industry for decades due to its anti-aging properties. Interestingly, this dates back to the ancient civilizations like Egyptians, who used copper as part of their make-up. Now, there are companies that make copper infused pillows that claim to also have positive effects on overall health, including skin health. Copper pillow slips have copper oxide particles embedded in fabrics like polyester or nylon, and the science behind these cases is pretty sound. Research shows that using a copper pillowcase has antimicrobial and healing benefits for breakouts and may reduce and prevent fine lines and wrinkles.

6. Kitchen Tools

Copper can also be used for many daily implements, including kitchen pots and pans, making for some of the most beautiful kitchen tools. But for the cook – professional or home – copper means one thing and that’s cookware. It’s expensive and high maintenance but also one of the most coveted pieces of kitchen kit. Rewind 100 years and copper cookware would have been the de facto choice in hotels, restaurants, and stately homes. Walk into the kitchens at Petworth House in West Sussex – now a National Trust property – and feast your eyes on some of the 1,000 pieces of copperware that are in their collection. In the 19th century, copper cookware – stock pots, sauté pans, jelly moulds – were used at Petworth to make up to 100 meals per day. Copper cookware was the kitchen workhorse.