Permeability

Reference data and engineering information about permeability for miscellaneous applications.

permeability

Overview

Engineering reference data for Permeability in miscellaneous.

Key Formulas

Unit Conversion

$y = x \cdot k$

Multiply by conversion factor.

Linear Interpolation

$y = y_1 + \frac{(x - x_1)(y_2 - y_1)}{x_2 - x_1}$

Estimate between two known points.

Percentage

$p = \frac{\text{part}}{\text{whole}} \times 100\%$

Part as fraction of whole.

Variables

Symbol	Description	Unit
$x$	Input value	—
$y$	Output value	—
$k$	Conversion factor	—

25 rows

Permeability and relative permeability of various materials at room temperature.
Medium	Permeability (µ)(H/m)	Relative Permeability (µ/µ₀)
Air	1.25663753×10⁻⁶	1.00000037
Aluminum	1.256665×10⁻⁶	1.000022
Austenitic stainless steel¹)	1.260×10⁻⁶ – 8.8×10⁻⁶	1.003 – 7
Bismuth	1.25643×10⁻⁶	0.999834
Carbon Steel	1.26×10⁻⁴	100
Cobalt-Iron (high permeability strip material)	2.3×10⁻²	18000
Copper	1.256629×10⁻⁶	0.999994
Ferrite (nickel zinc)	2.0×10⁻⁵ – 8.0×10⁻⁴	16 – 640
Ferritic stainless steel (annealed)	1.26×10⁻³ – 2.26×10⁻³	1000 – 1800
Hydrogen	1.2566371×10⁻⁶	1
Iron (99.8% pure)	6.3×10⁻³	5000
Iron (99.95% pure Fe annealed in H)	2.5×10⁻¹	200000
Martensitic stainless steel (annealed)	9.42×10⁻⁴ – 1.19×10⁻³	750 – 950
Martensitic stainless steel (hardened)	5.0×10⁻⁵ – 1.2×10⁻⁴	40 – 95
Nanoperm	1.0×10⁻¹	80000
Neodymium magnet	1.32×10⁻⁶	1.05
Nickel	1.26×10⁻⁴ – 7.54×10⁻⁴	100 – 600
Permalloy	1.0×10⁻²	8000
Platinum	1.256970×10⁻⁶	1.000265
Sapphire	1.2566368×10⁻⁶	0.99999976
Superconductors	0	0
Teflon	1.2567×10⁻⁶	1
Vacuum (µ₀)	4π×10⁻⁷	1
Water	1.256627×10⁻⁶	0.999992
Wood	1.25663760×10⁻⁶	1.00000043

Source: engineeringtoolbox.com

Note on Austenitic Stainless Steel: Its permeability is not fixed like ferritic, martensitic, or duplex steels. In the fully austenitic condition, it behaves as a paramagnetic material with a relative permeability approaching 1.0. This low permeability makes it suitable for applications requiring a non-magnetic material.

References

Original Source

Source: engineeringtoolbox.com