The authoritative public forum
  for Metal Finishing 1989-2025
  

  -----

Science: does rust affect conductivity of metals?

Hey I'm an 8th grader and am doing a science fair project on if rust affects the electrical conductivity properties of iron and steel. Does anyone happen to know what the Ohms are for pure iron and compounds of steel? My ohmmeter isn't working...

Kyle S.
- Atlanta, Georgia
October 17, 2010

---

Hi, Kyle. Talk to your parents about the broken ohmmeter because if your science project would now depend on just asking someone for the answer, your project probably isn't really worth submitting :-(

Metals are very conductive, and rust is not metal. So yes, you should expect the rust to impede the conductivity.

You can google for "conductivity of iron" or conductivity of steel" and you will get useful answers. But you will learn that the Ohms ("resistance") that you measure will also depend upon the size of the block of steel or iron, as well as the material it is made from. The longer it's length, the more resistance the electricity will encounter during it's trip from one end to the other. The larger it's cross section, the lower the resistance. Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 19, 2010