Q: I am looking for a bolt that will withstand working temperatures of around 800 degrees. We are having issues using grade 9 bolts that after multiple oven cycles we are having to cut the bolts off due to them being locked up. We need a bolt that will withstand heat and not lock up. The bolts are withstanding a good amount of force while under heat. I am having a hard time finding a bolt with a good rate of thermal expansion.
A: Inconel 625 Screws are something you should definitely consider. Inconel 625 is a great high temperature material for bolts, as it is very oxidation resistant and well suited for your operating temperatures of 800C. As it is resistant to oxidation, you will be much less likely to enbrittle and break an Inconel bolt. Additionally a moly-disulphide anti-seize is a good idea to apply to the bolts which will to help minimize any kind of galling. Here are some links that may help you.