Tag: FDA approved polymer fasteners

PTFE Screws for Laboratory Corrosion

I’m running some laboratory testing in a mixed acid environment and would like to use a corrosion resistant polymer as apposed to a metal. I’ve tried PEEK screws but am still struggling a bit with some acids. Is there anything better?

PEEK screws provide reasonable corrosion resistance to most acids but is more geared for high strength applications in moderately corrosive applications. For a polymer fastener that is more corrosion-focused, I would go with PTFE fasteners. PTFE screws will not provide the strength of PEEK, but they are much more corrosion resistant. If the strength of PTFE screws are good enough (approximately 3900psi at room temperature) for your application then you likely improve the corrosion resistance of your fasteners.

PEEK Screw Strength vs FDA Approved PTFE Screws

Q: I work in the food industry and need a larger sized polymer fastener sized 1/4-20 x 2.5″. I tried PTFE but it isn’t does not seem to have enough strength. It also needs to be FDA approved and offer moderate corrosion resistance.

A: Not knowing the specific strength requirements of your application, I would suggest a PEEK fastener. PEEK screws are FDA approved and offers decent corrosion resistance. PEEK is also much higher strength than PTFE which will be important in a larger bolt. PTFE only can provide a yield strength of 1450 psi compared to PEEK screws which offer 13,600 psi in yield.