Q: I have a laboratory applications that uses about 25% sulfuric acid at room temperature to 100F. I’d like to use a polymer rather than a metal if possible. I tried PTFE screws because I thought they were corrosion resistant, but they need to be replaced often because they can’t handle the work load. Is there another polymer I can use?
A: For a stronger polymer combined with corrosion resistance, you may want to consider PVDF screws. PVDF offers a good level of corrosion resistance and has a tensile strength around 2000-3000 PSI stronger than PTFE screws. PVDF screws are known for their balance of corrosion resistance and strength, where PTFE is best for corrosion resistance alone. PEEK screws could also be an option as they are 4-10x stronger than PTFE, but PEEK may weeken a bit with sulfuric acid at that temperature and concentration: