Q: I don’t see 316 on your sight but would you know if 316H material can be useed at 1500F?
A: I believe 316H will survive 1500F without significant oxidation. However, please be aware, at that temperature, the material will lose a significant % of its strength. The material already starts out at the very low end of material strengths. At 1500F, you may get <10% of the tensile strength from the material.
So, although 316H will not oxidize from the temperature, we still would not recommend it as a fastener due to the low strengths at those temperatures.
Here is a page on high temperature fasteners that can be used at 1500F and beyond:
https://www.extreme-bolt.com/applications-high-temperature.html