Copper Wire


Copper is one of the most versatile and commonly used materials. Copper has a wide range of uses, some of these uses are power transmission lines, electrical wiring, and spark plugs. In this article, you will learn about copper’s conductive properties, size chart, and alternatives to the conductive alloy.


Copper’s excellent electrical and thermal conductivity provides the most essential, free-moving electrons which electrical wiring requires. Wires must have low resistivity to electrical currents to ensure a power source can push current through. However, it’s the combination of these following properties that make copper the industry standard choice.

bare copper wire
Courtesy: ParaWire

Electrical Conductance

Electrical conductance is the capacity to allow electrical current flow. When it comes to electrical conductivity, copper ranks the second highest next to silver. Oxygen can also be purposely added to increase copper’s electrical conductivity. Copper is the industry-first choice because it is not considered a precious metal.

Thermal Conductance

There are many applications that require materials with high thermal conductivity. Copper is in components for air conditioning units, heat sinks, vehicle radiators, and much more in most cases. This is a result of thermal conduction that is approximately 30 times stronger than the common stainless steel and 150% stronger than another strong thermal conductor, aluminum.


When it comes to a metal’s resistance, its reactivity to oxygen plays a large factor. Copper’s reactivity to oxidation, also known as, corrosion, is very low. This attribute is important for durability for copper’s use in applications like radiators, electrical wires, pipes, and pans.

Alloy Compatibility

Copper combines easily with other metals to create alloys. This is most useful for the creation of busbars, pipework, and power distribution systems. Copper strength and hardness can be increased by alloying by sacrificing conductivity.


Ductility is the ability to be shaped or bent without damage. Copper falls into this category and is also very lightweight. The arrangement of atoms is a face-center cubic structure. This structure means there are more internal planes between the atoms which allow metal atoms to move without cracking. This proves to be most helpful in soldering and piping. This makes copper useful in computers, cars, TVs, phones, and lighting.

Bunch of bent 14 ga copper wire
Courtesy: White Fox Beads


Copper and its associated alloys are strong. They resist breaking and becoming brittle even when taken to temperatures below 0° Celsius. Pure copper reaches a tensile strength of 18 KSI (18,000 lb / in2) and breaks at approximately 85 pounds of force.


Copper is in many military tools and applications because it is non-magnetic and non-sparking. Even though Copper is non-magnetic, there are still interactions with magnets that make Copper useful. Slowing down magnets with Copper is common in braking systems for high-speed trains. It is useful in converting high-speed momentum to electrical currents, a reaction called Force Field Motion Dampening.

AWG Copper Wire Table Size and Data Chart at 100°F

When it comes to cable sizing, having too much voltage drop makes it difficult for current to travel through copper wires. According to the NEC Code Book, the maximum amount of voltage drop should not exceed 5%. For standard industrial applications, a cable sizing/maximum distance tool can help calculate a proper size.

Another point to keep in mind is the space in between wires to prevent overheating. This pertains to typically Conduit Filling in raceways. Raceways need proper sizing so conductors can fit without overheating but for the maximum amount of copper conductors to occupy the raceway.

copper wire table size and data chart



In the early stage of its use, copper provided wires in telephone poles. Copper’s free-moving electron structure allows signals to be sent through telephone wires easily. Telephone poles use copper unshielded-twisted pair (UTP) wiring. The twisted pairs provide increased bandwidth.

Supplying Electricity

Copper wires provide a means of transport for power sources to deliver energy to homes, commericial, and industrial facilities. Copper’s high ductility allows it to shape into numerous places in a household to supply power anywhere. Another major reason Copper appears frequently in power transmission is that it is not an expensive precious metal.

Automobiles and Marine Wire

Climate durability is in high demand for industries like automobiles and underwater applications. Therefore, copper demand increases by around 5% in these industries every year. Aside from being extremely electrically conductive, Copper provides benefits like ductility, high melting point, and corrosion resistance. In places where climate changes frequently like these industries, copper provides safe and efficient use.


Pure Silver stranded wire
Courtesy: Ebay


When considering other metals with a similiar conductivity profile, silver provides a strong potential alternative. Silver is approximately 7% more conductive than Copper by length. However, longer lengths of silver wire reduce its efficiency as an electrical conductor. It also oxidizes at a faster rate than Copper. Silver still provides a viable option for niche electronics that require high levels of conductivity over shorter wire lengths.


Aluminum has some basis, albeit mostly historical, as a subsitute for copper. It is lighter than copper but much denser. This means that it is more resource-efficient so more yield can be produced from the same amount of material. However, since it is less conductive than copper, the wire thickness must be larger to compensate, which means cables of this material are inherently thicker. Also, aluminum is more brittle so it is less reliable as a conductive material compared to copper.

solarus fiber optics
Courtesy: atlantech

During the late 1960s and early 1970s, aluminium wiring saw much more frequent use in commerical and residential applications. However, aluminum thermally expands much more than copper. The repeated expansion and contraction loosens wire. Loose wires are prone to sparking and eventually may result in a fire.


In recent years, the cost of copper has been slowly rising while the installation of fiber-optic wires has decreased. This change in price has put fiber-optic wires in a more cost-competitive position for the cable/wire market. Currently, fiber-optics dominates the network transmission market in terms of reliability in data connection. This is mainly because of the materials’ significantly larger bandwidth capabilities. This transitions into greater transmission speeds over greater distances.

The growth rate of data has been increasing exponentially since the recent boom of consumer data services and is looking to continue to grow. Copper wires use electrons for data transmission. Fiber-optics wires are made of hair-thin strands of glass that carry photons for data transmission. Fiber-optics are not affected by electrical interferences. Photons move much faster than electrons and have stronger signal durability over long ranges.