Because of its thickness, solid wire has a decreased surface area that reduces dissipation. Because of the given thickness of stranded wire, i.e., it’s thinner, there are more air gaps and a greater surface area in the individual strands of wire. Therefore, it carries less current than similar solid wires can.

The thin wire will conduct electricity, but there is more electrical resistance. The thicker wire is like the four lane highway. There’s a lot less electrical resistance, and as a result, that light bulb burns brighter because more electricity can reach it.

In general, solid cables are better electrical conductors and provide superior, stable electrical characteristics over a wider range of frequencies. They are also considered more rugged and less likely affected by vibration or susceptible to corrosion since they have less surface area than stranded conductors.

All wire sizes are available in stranded, however not all cabling styles are made with stranded wire (i.e. NM/Romex). Any sort of flexible cordage is only stranded. You can use stranded wire anytime you can get it, and your terminations are listed for stranded wire.

Solid wire, also called solid-core or single-strand wire, consists of one piece of metal wire. Solid wire is useful for wiring breadboards. Solid wire is cheaper to manufacture than stranded wire and is used where there is little need for flexibility in the wire.

In general, breakers don’t care what sort of wire is attached. However, it’s generally good practice, to use a bootlace ferule crimped onto finely stranded wire to stop strands spreading. It’s essentially where there’s any form of screw connection.

To twist two wires together, you first need to strip the insulation off the wires. Next, hold the wires side by side and twist them together with your thumb and forefinger. The resulting connection should be fairly strong and hold together when a small tug is applied.