I was wondering if anyone knew of links to different websites that stated the coefficients of resistance for different metals. Mainly copper, and steel equipment. I am working in a mill and my supervisor asked me to find out these values. There is copper cable running as ground and conductors, and steel equipment which connect to a ground buss which inturn eventually meets up with the grounding cable conductors. Basically I am looking for general values, and since the resistance for steel varies due to different types of steels, a range or approximate value would help me out. Thanks.