Electrical Wire, Cable and Wiring Supplies

Gauge, strands and jacket: the wire spec that must match the load

Wire leads this aisle, followed by the parts that terminate and route it, and gauge is the first decision: a lower AWG number means a thicker conductor that carries more current. Thin 18 and 22 AWG suit signal, control and low-current hookups, while building circuits need heavier wire sized to the breaker. Solid wire is rigid and best for fixed runs inside walls; stranded wire flexes and tolerates vibration, so it is the choice for machines and moving parts. Jacket color is not just looks: black, white and green often mark hot, neutral and ground conductors in North American wiring, so follow your local code.

Lugs, connectors and raceway: matching the part to the wire and the metal

Copper and aluminum expand and corrode differently, so lugs and splices carry a marking: CU for copper, AL for aluminum, AL/CU for either. Tin-plated aluminum lugs resist oxidation. A crimp lug must match the wire's size range and be pressed with the correct die, because the barrel is made for a specific gauge. Surface raceway and wire hiders conceal cable along walls and are sized by width, with separate inside, outside and right-angle corner pieces. Solder listings differ by alloy: tin-lead melts at a lower temperature than lead-free but contains lead.

Questions about Electrical Wire, Cable and Wiring Supplies

Which wire gauge suits a 15 amp or 20 amp circuit?

In North American house wiring, 14 AWG copper is the usual match for a 15 A breaker and 12 AWG for a 20 A breaker. Other countries use metric sizes and different rules, so follow your local code and never fit wire thinner than the breaker requires.

Can I join aluminum and copper wire?

Not with a plain copper connector. Use a connector marked AL/CU and the compound or fitting its maker specifies, because the two metals expand and corrode differently and a poor joint can overheat over time.

What is the difference between solid and stranded wire?

Solid wire is a single conductor: it holds its shape and pushes neatly into terminals, which suits fixed runs. Stranded wire is many fine strands: it bends easily and survives vibration, but needs the right crimp, ferrule or terminal to avoid stray strands.