Solid or Stranded Wire?

Solid wire consists of a single, solid strand conductor whereas stranded wire is made up of multiple strands grouped together for added flexibility. Usually, solid wire is used for stationary installations (such as inside walls, conduits, or other places where the wire won’t need to move) and where flexibility is not a concern.

Although less flexible than stranded wire, solid wire will hold its shape better when bent. It also has slightly better current-carrying capacity and is typically more cost-effective. Additionally, solid wire is more durable in environments where there’s less movement or stress.

Stranded wire, being far more flexible, is the better choice for applications where wires are subjected to repeated movement or vibration (such as in automotive and robotics) or in smaller devices where tight bends and flexibility are needed.

A typical wire data sheet lists the construction of stranded wire as two numbers (X/Y), with the first number (X) representing the number of strands and the second number (Y) indicating the individual gauge of each strand. A higher number of strands typically means greater flexibility. Standard wires can range from several to dozens of strands, while flexible control cables can use hundreds of strands to withstand frequent motion or tight routing requirements.

**Soldering **When choosing between solid and stranded wire for soldering, each has specific strengths. Solid wire is easier to insert and solder into through-holes or vero boards due to its rigidity, making it convenient for stationary applications where the connection won’t experience frequent movement. Stranded wire, however, provides a stronger bond with solder and is better suited for environments subject to vibration or movement, as its multiple strands create a more resilient joint.

Breadboards Solid wire works best in breadboards, as its single strand fits securely into the contacts and holds its position. Stranded wire can be problematic in breadboards, as the strands may separate when inserted, often requiring twisting or tinning to remain intact.

**Screw Terminals **For screw terminals, solid wire provides a secure connection without the risk of fraying. Stranded wire should be twisted and tinned or used with ferrules to prevent fraying, ensuring that all strands are held together for a reliable connection.

Connector Crimps

Connector crimps are generally unsuitable for solid wire because it lacks the flexibility needed for a secure compression. Solid wire’s rigidity can result in a weak connection, whereas stranded wire conforms well under pressure, creating a reliable bond

The Verdict:

Opt for stranded wire unless you need to prioritize cost or require the wire to retain its shape independently. Stranded wire offers better flexibility and durability, making it suitable for most applications.

For additional reading: Nassau, Sparkfun

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