Q:We have an anodizing process that sends low voltage current through aluminum bars. We have been using 316 stainless bolts, but over time the electricity heats the bolts up red hot, then we lose clamping force. The tanks contain a solution of 15% sulfuric acid, so there is some corrosion protection required. Can you recommend a material to use
and provide a quote?
A: From a materials perspective, we believe Monel bolts would be a great choice. Monel is a nickel copper alloy which will have very good conductivity, corrosion resistance to sulphuric acid and strength. Depending on the bolt strength that you need will determine which grade of Monel is required, Monel 400 or Monel K500 (age hardened
version). Monel 400 bolts will have a tensile strength around 80ksi whereas the Monel K500 bolts will approximately double the tensile strength to 160ksi. Other properties of corrosion resistance and electrical conductivity will be approximately the same.