Stranded vs. Solid Conductor Wire
Electrical wire comes in two conductor configurations: solid and stranded. Both carry current equally well at the same gauge, but their physical properties make each better suited for different installation scenarios.
Solid Wire
Solid wire consists of a single, continuous metal conductor surrounded by insulation. It holds its shape when bent, making it easy to work with at junction boxes, outlets, and switches. Solid wire is the standard choice for permanent residential wiring in the 14 AWG to 10 AWG range. Romex (NM-B) cable uses solid conductors. The main advantage is clean, reliable connections at terminal screws and push-in connectors.
Stranded Wire
Stranded wire is made up of multiple thin conductors twisted together to form a single conductor. This construction makes the wire significantly more flexible than its solid equivalent, which is a major advantage when pulling wire through conduit, especially in long runs or runs with multiple bends. Stranded THHN/THWN is the standard for commercial conduit installations. In larger gauges (6 AWG and above), almost all wire is stranded because solid conductors of that thickness are extremely rigid and difficult to work with.
When to Use Each Type
Use solid wire for standard residential branch circuits wired with NM-B cable, short conduit runs, and any application where the wire will be terminated on screw terminals or push-in connectors. Use stranded wire for conduit runs (especially longer or complex runs), larger gauge applications (6 AWG and above), flexible connections, and commercial installations. When using stranded wire on screw terminals, wrap the conductor clockwise around the screw for a secure connection, or use a wire ferrule for the cleanest termination.
IB Lighting carries both solid and stranded wire in all common gauges. Call (800) 674-9019 for pricing and bulk availability.