Is stainless steel a viable electric conductor

I've seen stainless used as contacts but copper is the norm.
In non-critical short distance applications its probably OK.

 

Depends on the type of stainless.
http://www.tibtech.com/conductivity.php

 

From the supplied table, Steels are 50X worse than copper.

 

Stainless steel is a piss-poor conductor of both electricity and heat (that is why stainless frying pans have a copper or aluminum bottom to spread the heat evenly). It also has a tendency to work-harden and will become brittle and break if repeatedly bent back and forth as is sometimes typical with wiring. It is pretty hard to improve on copper without spending ridiculous money for exotic metals.

 

The "backbone" of the Audi A8's wiring harness is IIRC made out of a long flat and bent aluminium part. I read an article by the company who produces that stuff in ATZ journal, awesome stuff.

 

and after have owned an A8L, I can tell you that probably wasn't the best decision, the dang thing should've been called christine! the number of electrical gremlins and my favorite, self running components had me wondering if I needed a priest instead!

If memory serves me correctly BMW back in the late 70's used aluminum plating in the wiring harness, didn't turn out so well a decade or so later.

the best elements are; Silver, Copper, Gold and Lead. beyond that you get into exotic materials for components, nichrome, tantalum, tungsten, thorium etc..

 

I agree on your first 3 picks, but lead? Id remove lead from that list. It has a low conductivity. At least, by 2 powers of 10. Lead is good for a suit during a nuclear war.......

 

GM used an aluminum wiring harness for the rear lighting assemblies for about 15 years, late 70's to early 90's. Probably worked will in Arizona, New Mexico and Nevada but it didn't work well here in the "corrosion belt'

 

Aluminum is a poor choice for wiring. The oxide that coats the surface is not a good conductor even though the base metal below the surface is. The result is a lot of intermittent problems and in some instances such as when aluminum was widely used in home wiring, FIRE. Today, aluminum wiring requires special devices and flux on connections to keep resistance to a minimum.

Copper, on the other hand is still very conductive even when oxidized.

 

It is also barely magnetic.

 

Curious as to the application that you were planning on?

 

As a Electric Lineman in the Fl Keys,the majority of Switches,Bushings, Fused Cutouts,and Constuction related Parts were made out of Stainless Steel,due to the Corrosive Atmosphere The Atlantic Ocean Hurricanes and tropical storms we Encounered.

 

while I'd agree if the use of lead was for wiring due to lead being higher in resistance, but it's ability to abate corrosion and esp it's chemical reaction makes it useful in batteries. it's also used in solder as well, and the Pb free solder has a BIG whisker issue.

 

Power line conductors are aluminum, much because power loss is P = I^2*R. That is, you can decrease the power loss quadratically by decreasing the current, which you do by increasing the tension ('voltage').

That option is not available in car electrics, but for low-conducting metals another option is to increase the diameter of the conductor.

 

I would not use stainless in that application as the resistance of stainless in a DC application of 40amperes. copper is better suited to that task, esp since it's in the circuit for those high inductive transient spike ampere loads. copper scrap in various gauges can be picked up from many metal suppliers in socal cheap, try a local IMS -industrial metal supply, I get lots of scrap from them. copper sheet and bars for the spot price per lb.

as point of comparison, nichrome wire which is nickle chrome steel is used for large variable resistance coils. not a good idea where amperage will be high and frequency zero.

 

How are you going to make the electrical connections to the stainless? For pieces that short, the quality of these connections will be at least as important as the resistance of the bridge itself.

If you really mean "prototype" and not "something I'll put in my car and expect to work for months or years" stainless may work. But for anything real, I'd seriously prefer copper and would not use stainless if I had any other choice at all.

One easy and not unreasonably expensive source of copper is 12-gauge solid-core household wiring - strip the insulation and you have a nice ready-to-solder length of copper that's good for 100+ amps in 1" lengths. And if you're any sort of DIYer you probably already have a few feet of it lying around the house looking for a use, so the price is right.

If Birdman speaks up in this thread... Listen to him.

 

+100

 

I have used brass for the same purpose. It can be cleanly soldered to the existing brass terminals is part of why I like it.

I have attached a pic of a hidden auxiliary fusebox in a restoration, that uses hidden micro relays with all original wiring, and a supplemental hidden 12v "bus" wire (from the starter terminal) to the hidden fusebox.
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well Jim you're kinda cheating though JK
C36000? if so that's 61.5% Cu. ~35% Zn, so it's still a very good conductor with less resistance than iron and steel. But yes brass is a decent alternative to copper for buss-bars and switch points. The best is Silver, but who's got that kind of money!

On brass, the composition can become critical depending on voltage and amperage load of the circuit. unknown values may cause safety concerns. brass has a lot of variations and many different elements added into it. voltage drop due to increased resistance will cause an increase in the amp load, as the metal increases in temperature due to the amperage draw and wattage dissipation the resistance will increase as well, think slow burn fuse.

 

Okay, I'll play Johnny come lately and pee all over everything

But, seriously, I don't know what your application is exactly, but have you also taken into consideration the structural loads / demands, if any ???

Copper, and most of its alloys, are rather weak structurally (both in strength and in stiffness), especially in fatigue tolerance. So, if your piece is going to see any significant loads or cyclic loading, you may want to go with a "tough" alloy, such as BeCu (still an excellent electrical & thermal conductor) ---- or, at the very least, choose a high temper Copper / Copper alloy......

.......just sayin'