A.W.G. American Wire Gauge
American wire gauge (AWG), also known as the Brown & Sharpe wire gauge, is a standardized wire gauge system used since 1857 for the diameters of round, solid, nonferrous, electrically conducting wire. Dimensions of the wires are given in ASTM standard B 258. The cross-sectional area of each gauge is an important factor for determining its current-carrying capacity.
Increasing gauge numbers denote decreasing wire diameters, which is similar to many other non-metric gauging systems such as SWG. This gauge system originated in the number of drawing operations used to produce a given gauge of wire. Very fine wire (for example, 30 gauge) required more passes through the drawing dies than 0 gauge wire did. Manufacturers of wire formerly had proprietary wire gauge systems; the development of standardized wire gauges rationalized selection of wire for a particular purpose.
The AWG tables are for a single, solid, round conductor. The AWG of a stranded wire is determined by the cross-sectional area of the equivalent solid conductor. Because there are also small gaps between the strands, a stranded wire will always have a slightly larger overall diameter than a solid wire with the same AWG.
Vapers use different gauge wires for producing coils with varying resisitance, sometimes combining several gauges to produce the perfect coil with a single smaller gauge wire which acts as a fuse wire.
The most common gauge of wire used by vapers are 24-30. Altering the number of wraps is used to change the overall resistance of the coil.