What are Conductors?

A conductor is the core component of a cable that allows the flow of electrical current for power or data transmission. It is typically made of one or more metal wires which can be arranged in a variety of configurations. While a bare conductor can be used in some circumstances, like a grounding wire, most are covered in some type of insulation and/or protective jacket.

The term "wire" is often used to describe an entire cable, but it also refers to the strands that make up the conductor. You may also see conductors referred to as wires, e.g., "this cable is made up of three stranded copper wires."

Conductor Materials

Highly conductive metals allow free electrons to pass easily from one atom to the next-- that's the flow of electricity. The most common conductor material is copper, due to it's high conductivity, relatively cheap price, it's ductility (how easy it is to be drawn into thin wires without breaking), and it's flexibility and durability.

Aluminum is a popular, cost-effective choice, while gold and silver are reserved for special applications.

Thermocouple wires use alloys like chromel, alumel and constantin, as well as platinum, to measure temperature changes. They work when heat energy causes an electrical current to travel down one of two wires in a pair.

Conductor Coatings

Often, conductor wires are coated with other metals to improve or achieve certain characteristics like durability, conductivity, heat resistance, and melting point. For example, copper can be coated with nickel, or tinned to prevent corrosion. Copper can also be coated with gold, silver or palladium to improve conductivity.

Aluminum conductors can be coated with copper to increase strength and conductivity. Aluminum is also regularly coated with non-metal finishes to reduce oxidation.

Conductor Strand Types

Conductors are composed of either multiple strands of smaller wires, or a single, solid conductor. Solid conductors are typically limited to smaller wire sizes, 10 AWG and smaller. Between 8 AWG and 2 AWG, conductors may be solid or stranded. Larger than 2 AWG, almost every wire will be stranded for flexibility, strength and ease of manufacturing.

A single large conductor can consist of thousands of wire strands. Depending on total strand count, overall cable thickness and application, strand configurations include: concentric, bunch, rope, sector, segmental, compressed, compact and annular. How the strands are arranged not only affects cable flexibility, but it can also have a significant impact on AC resistance.

Conductor Sizes

As you saw above, conductor sizes are usually referred to by AWG, which stands for American Wire Gauge. There are other size designations including kcmil, MCM, and more. We cover more about sizes in the section about wire gauges. Suffice to say, the smallest standard wire diameter is 40 AWG, which is 0.0031 inches. The largest is 0000 AWG at 0.46 inches.

These wires can be used as strands in larger conductors, which can have diameters of nearly 8 inches, for the very largest cables. The thickest cables currently listed on our site are 750 MCM, about one inch in diameter.

Conductor Configurations

Single conductor cables are composed of a single wire, either solid or stranded, while multi-conductor cables consist of multiple wires. Twisted pair cables are composed of two insulated wires twisted together, while coaxial cables are composed of an inner conductor surrounded by an outer conductor and insulation. In flat festoon cables, conductors are lined up in a row, creating a ribbon-like cable that easily droops or "festoons" to accommodate machinery like a warehouse crane moving along a track. Shielded cables are composed of an inner conductor surrounded by a shield of metal foil or braided wire, which reduces electro-static interference between conductors in the same cable, or other electrical sources outside the cable.