Monel Bolts Over Nickel 200 for Aqueous Hydrofluoric Acid

Q: I’m using aqueous Hydrofluoric acid in a silicon etching process but amy Nickel 200 bolts aren’t holding up. Is there a better material I can use?
A: Nickel 200 fasteners are excellent for use in anhydrous hydrofluoric acid, but in the aqueous form of HF acid they offer limited resistance. The good news is that there is a solution. Monel 400 is one of the few materials that can offer protection from hydrofluoric acid corrosion.  Monel bolts have excellent resistance to HF in all concentrations up to the boiling point.