Q: I’m having trouble with corrosion of our bolts in a sour gas well environment and we are currently using a super duplex stainless steel. Can you help me with a bolting material that would be improved?

A: Hastelloy C276 bolts are ideal for sour gas environments and would be an improvement on Super Duplex steel bolts. Hastelloy C276 bolts are known for their resistance to sulfuric acid even at high temperatures and concentrations. Here is a chart showing Hastelloy C276 resistance to sulfuric acid that should help you. Hastelloy C276 bolts also provide excellent resistance to chlorides which can also be common in sour wells.