What solvents are not compatible with PEEK?

Very few solvents have been shown to not be compatible with PEEK. Two common solvents are known to directly attack the material: concentrated sulfuric acid and concentrated nitric acid. Other less common solvents that attack PEEK polymer include: halogenated acids such as hydrofluoric acid; hydrobromic acid; hydroiodic acid (hydrochloric acid is approved for use in most applications); and pure halogenated gases. There are a few other chemicals that exhibit a physical swelling effect on PEEK tubing, namely methylene chloride, DMSO, and THF. However, these chemicals do not adversely affect PEEK fittings. Please see our Chemical Compatibility chart.

Because the list of adverse chemicals is so short, PEEK is an excellent alternative to most other materials available commercially today, including stainless steel and titanium, as well as other polymers.