I remember telling someone in a forum about using stainless steel bolts as a shunt for use as a cheap current measurement. Someone else said that shunts are made with exotic (aka expensive) materials with very low thermal coefficients of resistance. I found this chart not too long ago and thought I would post it.
As you can see, stainless steel has a negligible coefficient. So, I feel vindicated. Stainless steel is exotic by the way. It is just mass produced and used for construction, thus making it pretty cheap.