Q: I’m in need a high strength bolt that can not only withstand temperatures of 1000F but also be exposed to chemical contaminants from time to time. The 1000F is the max, probably not the constant. Strength would need to be around 150ksi. Contaminants would be salts and some low concentrations of downstream acids.
A: For a high temperature, high strength bolt that also provides chemical resistance, there are three materials you should consider, Titanium Gr5, Monel K500 and Inconel 718. Which is best will depend on the exact requirements of your application. From a strength point of view all the materials should be OK, with Titanium Gr5 bolts having a typical Ultimate Tensile of around 148KSI, and Monel K500 and Inconel 718 bolts at 160 and +200KSI respectively. Inconel 718 fasteners would definitely be the best you could get with a combination of strength, high temperature resistance and corrosion and depending on the acids you are dealing with K500 or Titanium Gr5 may do the job effectively too.