Q: I saw on your high temperature chart that Molybdenum is listed twice. I’m confused, which high temperature should I use?
A: Both high temperatures are accurate, depending on the situation where you are using Molybdenum fasteners. Molybdenum screws can be used up to 2912F only if it is used in a vacuum – meaning an air/oxygen free environment – otherwise it will rapidly oxidize immediately into a gas (always surprises people). If you are using Molybdenum in an air/oxygen environment, the maximum temperature you can use this metal is 1112F. For extremely high temperature environments (above 1500F) where air or oxygen is present it is best to use Waspaloy, Inconel or Alloy 330 fasteners.