Electrical Resistivity of Carbon Steel

\rho_{\mathrm{steel}} = 1.6 \times 10^{-7}\ \text{Ω}{\cdot}\text{m}

Value	1.6e-7 Ω·m
Status	Measured: ± 4.00e-08 Ω·m (0.25 relative)
Source	ASM Handbook, Vol. 1 / CRC Handbook of Chemistry and Physics
Categories	Material Properties Engineering & Trade electrical-trade

ρ_st in every electrical resistivity unit

ohm meter	1.6000000e-07 Ω·m
ohm centimeter	0.000016 Ω·cm
microohm centimeter	16 μΩ·cm
nanoohm meter	160 nΩ·m

Learning zone

Steel is a mediocre conductor: an order of magnitude worse than copper, and far more variable, because carbon, manganese and alloying additions all scatter electrons. Values from 1.0 to 2.0 × 10⁻⁷ Ω·m are all legitimately "steel". Stainless is worse still at about 7.2 × 10⁻⁷ Ω·m, roughly 43 times copper.

This is exactly why steel is used where you want resistance and not where you want conduction. Resistance heating elements, induction-heated workpieces and resistance spot welding all exploit it; ACSR transmission cable puts a steel core inside aluminium strands purely for tensile strength and expects it to carry little current. The magnetic complication matters too: steel is ferromagnetic, so at power frequencies skin effect and hysteresis make its effective AC resistance much higher than the DC value — which is why a steel conduit carrying only one phase of a circuit heats up, and why the NEC requires all conductors of a circuit in the same ferrous raceway.

Used by these solvers

Resistance of a Wire (R = ρL/A)

R = \frac{\rho L}{A}