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.