In the United States how is the thickness of wire named?

• A. 0 is thickest; thinner wires have larger numbers.
• B. 0 is thinnest; larger numbers indicate thicker wires.
• C. Higher numbers indicate thicker wires.
• D. Thickness is named by color codes.

Answer: (B)

In the United States, wire thickness is named using the American Wire Gauge (AWG) system. The diameter of the conductor increases as the gauge number decreases, so thicker wires have smaller numbers and thinner wires have larger numbers. For example, 12 AWG is thicker than 14 AWG, and 0 AWG is thicker than 1 AWG, 2 AWG, and so on. Higher-numbered gauges like 40 AWG are very thin. Color codes are not used to name thickness. So the standard rule is the opposite of saying 0 is the thinnest and larger numbers are thicker; in reality, 0 gauge is thicker than higher-numbered gauges and larger numbers indicate thinner wires.