Q: I have an application where I need pan head, insulating, high vacuum compatible, screw. It will also need to be usable at a service temperature up to 150C. Do I need a ceramic?

A: Though ceramics are excellent insulators, they are usually only used for high temperature applications, where polymers are not compatible. For example Alumina ceramic has a usable limit of 1650°C. Since this is a relatively low temperature, your best bet is a polymer like PEEK or PVDF screws. Depending on the strength, inertness and chemical resistance needed will determine which polymer PEEK or PVDF is best for your fasteners.