Available bulk resistivity values (ρ) and relative permeability (μr)used to calculate skin depths (δσ) can vary considerably
depending on the source. In fact, the values for permeabilities are so far-ranging that I hesitated to even include any of them in the table.
The ones used here are typical, gathered from many of the links listed at the bottom of the page. Therefore, it is
incumbent upon the user to determine his own value based on a trusted source. Even NIST[1] and CRC[2] do not fully
agree on bulk resistivity values for materials as well-known as copper and aluminum. Most common conductors used in cabling have a relative
permeability of very near unity (1).
Note that ferromagnetic materials often experience a falloff in relative permeability as frequency increases. For example least one investigator[3] has measured a value as low as 1 for nickel at 10 GHz.
Here is the equation for skin depth Here is a
skin depth calculator
|
Aluminum |
Al |
2.65 |
1 |
81.9 |
25.9 |
8.19 |
2.59 |
0.819 |
0.259 |
|
Beryllium |
Be |
3.3 |
1 |
91.4 |
28.9 |
9.14 |
2.89 |
0.914 |
0.289 |
|
Brass |
Cu70/Zn30 |
7 |
1 |
133 |
42.1 |
13.3 |
4.21 |
1.33 |
0.421 |
|
Bronze |
Cu89/Sn11 |
15 |
1 |
195 |
61.6 |
19.5 |
6.16 |
1.95 |
0.616 |
|
Carbon |
C (graphite) |
1375 |
|
1866 |
590 |
187 |
59.0 |
18.7 |
5.90 |
|
Cadmium |
Cd |
7.3 |
|
136 |
43.0 |
13.6 |
4.30 |
1.36 |
0.430 |
|
Chromium |
Cr |
13.2 |
1 |
183 |
57.8 |
18.3 |
5.78 |
1.83 |
0.578 |
|
Cobalt |
Co |
6.34 |
600 |
5.8 |
1.6 |
0.52 |
0.16 |
0.052 |
0.016 |
|
Constantan |
Cu60Ni40 |
49 |
|
352 |
111 |
35.2 |
11.1 |
3.52 |
1.11 |
|
Copper |
Cu |
1.69 |
1 |
65.4 |
20.7 |
6.54 |
2.07 |
0.654 |
0.207 |
|
Dural |
Al95/Cu 4/Mg 1 |
5 |
|
112.54 |
35.6 |
11.3 |
3.56 |
1.13 |
0.356 |
|
Gallium |
Ga |
15.5 |
|
198 |
62.7 |
19.8 |
6.27 |
1.98 |
0.627 |
|
Gold |
Au |
2.2 |
1 |
74.7 |
23.6 |
7.47 |
2.36 |
0.747 |
0.236 |
|
Graphite |
C |
783.7 |
|
1409 |
446 |
141 |
44.6 |
14.1 |
4.46 |
|
Inconel alloy 600 |
Ni72/Cr16/Fe 8 |
103 |
1 |
511 |
162 |
51.1 |
16.2 |
5.11 |
1.62 |
|
Indium |
In |
8.8 |
|
149 |
47.2 |
14.9 |
4.72 |
1.49 |
0.472 |
|
Iridium |
Ir |
5.1 |
|
114 |
35.9 |
11.4 |
3.59 |
1.14 |
0.359 |
|
Iron |
Fe |
10.1 |
500 |
7.2 |
2.3 |
0.72 |
0.23 |
0.072 |
0.023 |
|
Lead |
Pb |
20.6 |
1 |
228 |
72.2 |
22.8 |
7.22 |
2.28 |
0.722 |
|
Lithium |
Li |
9.29 |
|
153 |
48.5 |
15.3 |
4.85 |
1.53 |
0.485 |
|
Magnesium |
Mg |
4.2 |
1 |
103 |
32.6 |
10.3 |
3.26 |
1.03 |
0.326 |
|
Mercury |
Hg |
95.9 |
1 |
493 |
156 |
49.3 |
15.6 |
4.93 |
1.56 |
|
Molybdenum |
Mo |
5.7 |
1 |
120 |
38.0 |
12.0 |
3.80 |
1.20 |
0.380 |
|
Monel alloy 400 |
Ni65/Cu33/Fe 2 |
49 |
|
352 |
111 |
35.2 |
11.1 |
3.52 |
1.11 |
|
mu-Metal |
|
47 |
30,000 |
2.0 |
0.64 |
0.20 |
0.064 |
0.020 |
0.0064 |
|
Nickel |
Ni |
6.9 |
200 |
9.3 |
3.0 |
0.93 |
0.30 |
0.093 |
0.030 |
|
Nichrome |
Ni80/Cr20 |
108 |
|
523 |
165 |
52.3 |
16.5 |
5.23 |
1.65 |
|
Palladium |
Pd |
10.8 |
1 |
165 |
52.3 |
16.5 |
5.23 |
1.65 |
0.523 |
|
Platinum |
Pt |
10.58 |
1 |
164 |
51.8 |
16.4 |
5.18 |
1.64 |
0.518 |
|
Potassium |
K |
6.8 |
|
131 |
41.5 |
13.1 |
4.15 |
1.31 |
0.415 |
|
Rhodium |
Rh |
4.7 |
1 |
109 |
34.5 |
10.9 |
3.45 |
1.09 |
0.345 |
|
Silver |
Ag |
1.63 |
1 |
64.3 |
20.3 |
6.43 |
2.03 |
0.643 |
0.203 |
|
Sodium |
Na |
4.9 |
|
111 |
35.2 |
11.1 |
3.52 |
1.11 |
0.352 |
|
Steel |
|
|
100 |
|
|
|
|
|
|
|
Tantalum |
Ta |
13.5 |
|
185 |
58.5 |
18.5 |
5.85 |
1.85 |
0.585 |
|
Tantalum Nitride |
TaN |
252 |
|
799 |
253 |
79.9 |
25.3 |
7.99 |
2.53 |
|
Tin (pure) |
Sn |
12.6 |
1 |
179 |
56.5 |
17.9 |
5.65 |
1.79 |
0.565 |
|
Titanium |
Ti |
54 |
1 |
370 |
117 |
37.0 |
11.7 |
3.70 |
1.17 |
|
Tungsten |
W |
5.4 |
1 |
117 |
37.0 |
11.7 |
3.70 |
1.17 |
0.370 |
|
Urnaium |
U |
27 |
|
262 |
82.7 |
26.2 |
8.27 |
2.62 |
0.827 |
|
Yttrium |
Y |
53 |
|
366 |
116 |
36.6 |
11.6 |
3.66 |
1.16 |
|
Zinc |
Zn |
5.96 |
|
123 |
38.9 |
12.3 |
3.89 |
1.23 |
0.389 |
|
Zirconium |
Zr |
44 |
|
334 |
106 |
33.4 |
10.6 |
3.34 |
1.06 |
1: National Institute of Standards and Technology
2: Chemical Rubber Corporation
3:
Microwave Characterization of Nickel, Stepan Lucyszyn, Imperial College London (thanks to Reto Z. for pointing
this out)
Related Pages on RF Cafe - Coaxial Cable
Specifications - Capacitor Dielectrics & Descriptions
- Dielectric Constant, Strength, &
Loss Tangent - Conductor Bulk Resistivity & Skin
Depths - Coaxial Cable Equations -
Coaxial Cable Specifications -
Coaxial Cable Vendors - Coaxial Resonator - Skin Depth Calculator
-
Coaxial Connector Usage Chart
|
