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resistance of various metals

I have seen charts that show how the resistance of various metals compare. What I haven't seen is a way to make determine how much larger say a stainless steel rod would need to be to have the same resistance as a copper rod of some given diameter. For example if I had a 30 awg copper wire and a 1" dia Stainless steel rod, even though the copper is a better conductor, in this case the 1" dia stainless steel rod is going to have less resistance. Is there a rule of thumb, or chart that tells how much larger to make a conductor to have equivalent resistance to copper?

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Chris W
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Reply to
Chris W
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"Chris W"

** Are you for real ????

Got no idea that a wire's or rod's resistance is * inversely proportional * to its cross sectional area ?

Ever figure out that two similar wires run in parallel have half the resistance of one ???

** A real dope -

even by the most humble standards of ham operators.

....... Phil

Reply to
Phil Allison

No chart that I'm aware of, but not difficult to calculate. Find a table of resistivities for metals eg

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calculate fromResistance = (resistivity * length) / x-sectional area.Hope this helpsAl

Reply to
Al Forster

.calculate fromResistance =3D (resistivity * length) / x-sectional area.Hope= this helpsAl

Easy to calculate from the equation Al gave. Total resistance is the same, total length is the same, so if you have a material that's eight times the resistivity, by the equation it will have to have eight times the cross-sectional area. Simple algebra.

Which means the resistivity chart the OP is looking at is actually the chart he needs -- if he has a calculator, he can divide the resistivity of stainless steel by the resistivity of copper, and that tells him how many times more cross-sectional area he needs.

And a newbie alert if Chris is doing the calculations to determine resistance instead of just calculating ratios -- watch your terms. Charts for resistivity are frequently expressed for CM, circular mils. One circular mil is the area of a circle 1 mil in diameter. This is *not* 1 square mil -- you need to convert!

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Good luck with your studies. Chris

Reply to
Chris

#Table_of_resistivities

You will have to look up or determine the resistivity of your specific stainless steel - there are a lot of different stainless steels.

- Don Klipstein ( snipped-for-privacy@misty.com)

Reply to
Don Klipstein

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