hello, I'm trying to figure out how much current different conducting materials can handle.
I've found a couple of tables showing diameters and power transmission, but only for copper.

how do figure out how much current a certain rod of Steel can handle?

specifically, I'd like to know if a 1/32" steel rod could handle 0.5 ampere and if a 3/32" steel rod would be able to handle 4 ampere.

 

3/32 is close in dia. to an 18 ga. wire, so the steel will do fine with the 4 amps. just be sure to get your terminals good and tight, preferably soldered.
have a look here - googled "steel wire ampacity"

http://forums.mikeholt.com/showthread.php?t=96603

 

3/32 is close in dia. to an 18 ga. wire, so the steel will do fine with the 4 amps. just be sure to get your terminals good and tight, preferably soldered.
have a look here - googled "steel wire ampacity"

http://forums.mikeholt.com/showthread.php?t=96603

Think you better have another look at the wire gauge table.
3/32" is 0.093, closer to 11AWG than 18AWG that is 0.040. 18 gauge is about half of the 11 gauge.

 

handle it and handle it without glowing red is a totally different beast.. Either one of those diameters will carry your amperage EASILY and much more..

I wonder why the question was asked though..

 

It also depends on the ambient temperature, humidity, etc;