Keywords: Skin depth by Zureks.png en Skin depth vs frequency for various materials The equation used for skin depth calculation was <math>\delta \sqrt 2\rho \over \omega\mu </math> where δ - skin depth ρ resistivity of the material ω angular frequency 2 frequency μ absolute magnetic permeability μ<sub>r</sub>μ<sub>0</sub> The materials are as follows Mn-Zn - soft ferrite 3C90 from Ferroxcube initial permeability 2300 initial 25 deg C 10 kHz and resistivity 5 Ωm based on catalogue data http //www ferroxcube com/prod/assets/3c90 pdf such ferrite is not a good conductor so the curve is shown here as dashed just for demonstration how much better such materials are at higher frequencies Al - aluminium relative permeability 1 resistivity 2 7e-8 Ωm based on data from MatWeb http //www matweb com/search/datasheet aspx MatGUID 0cd1edf33ac145ee93a0aa6fc666c0e0 Cu - copper relative permeability 1 resistivity 1 7e-8 Ωm based on data from MatWeb http //www matweb com/search/DataSheet aspx MatGUID ca486cc7cefa44d98ee67d2f5eb7d21f steel 410 - magnetic stainless steel 410 permeability 1000 and resistivity 5 7e-7 Ωm based on data from MatWeb http //www matweb com/search/datasheet aspx MatGUID e5556cce22794269972d2718806a8bc7 the highest value of quoted permeability 1000 is used for worst case scenario Fe-Si - grain oriented electrical steel around 97 Fe and 3 Si from AK Steel manufacturer permeability 29 000 and resistivity 5e-7 Ωm based on manufacturer bulletin http //www aksteel com/pdf/markets_products/electrical/Oriented_Bulletin pdf maximum value of permeability is read out from the radial plot and it is used to demonstrate the worst case scenario Fe-Ni - permalloy trade name of VACUUMSCHMELZE GmbH Co KG is Mumetall alloy mainly of Fe around 20 and Ni around 80 values of permeability 250 000 http //www vacuumschmelze de/index php id 496 L 2 and resistivity 5 5e-7 Ωm http //www vacuumschmelze de/index php id 497 L 2 are based on the manufacturer data Red vertical line indicates 50 Hz frequency <br> <br> own Zureks 2011 Cc-zero Skin effect Aluminium Copper Permalloy Steel |