Inconel bolts vs Alloy 330 at high temps

Q: I’m designing a furnace vent system for a continuous service high heat appliance (NFPA 211). The maximum furnace working temperature is 2100 deg F; design temperature is 2190 deg F. Will Alloy 330 or 310 SS bolts and nuts work for me?

A: You are at the absolute limit in terms of temperature for these fasteners for 310 or 330. (see https://www.specialfastenersbolt.com/applications-high-temperature.html). To determine if the fasteners will work in your application you need to understand the load that is required on each fastener. At those high temperatures, the fasteners will be weak so you must be careful about what is needed from a strength point of view. You might want to also consider Inconel 600.