Empirical reference data and conversion formulas for solid bare copper magnet wire across American Wire Gauge (AWG 10 to AWG 60) and metric equivalents. Dimensions represent bare conductor values prior to enamel or self-bonding (Backlack) insulation build addition.

Conversion Formulas & Parameters

Nominal bare conductor diameter ($d_n$) in millimeters for AWG size ($n$) is calculated per ASTM B258:

$$ d_n = 0.127 \times 92^{\frac{36 - n}{39}} \text{ mm} $$

Linear DC resistance ($R_L$) at $20^\circ\text{C}$ for annealed copper ($\rho = 1.68 \times 10^{-8}\,\Omega\cdot\text{m}$) is given by:

$$ R_L = \frac{0.02139}{d_n^2} \quad [\Omega/\text{m}] \qquad (d_n \text{ in mm}) $$

Note: Resistance values below apply strictly at $20^\circ\text{C}$. For higher operating temperatures ($T$), apply copper's thermal coefficient $\alpha_{20} = 0.00393/\text{K}$.

AWG to Metric Specification Matrix