Q: I need a material that can stay oxidation resistant at 2000F in a cyclic temperature environment. Any suggestions?
A: One of the best choices is Inconel 601, UNS N06601,which is highly resistant to oxidation up to 2200°F and can handle even severe thermal cycling. These Inconel bolts will offer good high temperature strength and retain ductility after long service exposure. Also an excellent choice would be an Alloy 330 bolt. They offer oxidation and carburization resistance to 2100F – just over your requirement. Alloy 330 bolts are also known for their ability to withstand cyclic conditions of temperature extremes from heating and cooling. Which fastener is better, Inconel or Alloy 330, will depend on your strength requirements at temperature.

Q: I’m running a process that has a huge swing in temperature fluctuations due to downtime and maintenance. The max temperature is around 1500F. Can you suggest a material that can handle this?
A: For processes that are faced with the dual dilemma of both high temperature and cyclic conditions, I would recommend alloy 330 bolts. Alloy 330 fasteners are known for their ability to perform under cyclic conditions of extreme temperature swings. In addition, alloy 330 has a maximum usable temperature of about 2100F which is well within your range. Click here for a link to a good mechanical chart for alloy 330 fasteners.

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.extreme-bolt.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.