PCTFE or PEEK?

Compare PCTFE and PEEK to determine the ideal material for your specifications.

Rule of Thumb: Choose PCTFE when you need excellent dimensional stability, very low moisture absorption, and strong performance in cryogenic or corrosive environments. Choose PEEK when you need high continuous-temperature capability, outstanding mechanical strength, and broad chemical resistance in demanding engineered parts.

PCTFE (Polychlorotrifluoroethylene)

PCTFE (polychlorotrifluoroethylene) is a semi-crystalline fluoropolymer distinguished by near-zero moisture absorption, excellent dimensional stability, and very low gas and vapor permeability. It maintains mechanical integrity across a wide temperature range, including cryogenic service down to approximately −400°F (−240°C), making it well-suited for valve seats, seals, gaskets, and precision electrical insulation components. PCTFE provides strong resistance to most corrosive chemicals and oxidizing agents, though it does not match PEEK in mechanical strength or upper continuous-use temperature. It is best specified when dimensional precision, low permeability, and chemical inertness in low-to-moderate temperature environments are the primary requirements.

PEEK (Polyetheretherketone)

PEEK (polyetheretherketone) is a semi-crystalline, high-performance engineering thermoplastic offering an exceptional combination of mechanical strength, stiffness, and thermal stability. It retains its properties at continuous service temperatures up to approximately 480°F (250°C) and resists a broad range of chemicals, including hydrocarbons, fuels, and organic solvents. PEEK is widely specified for precision machined components in aerospace, semiconductor fabrication, oil and gas, and medical applications where metal replacement or weight reduction is required. While it absorbs slightly more moisture than PCTFE, its significantly higher strength, modulus, and upper-temperature rating make it the preferred choice for structural and load-bearing applications.

PCTFE Applications

  • Cryogenic valve seats and seals
  • Gaskets and sealing components
  • Aerospace pump and valve parts
  • Liquid oxygen and cryogenic valve liners
  • Chemical processing components
  • Laboratory and analytical instruments
  • Nuclear and high-radiation service parts (application-dependent)

PEEK Applications

  • Bushings, bearings, and wear pads
  • Pump and valve components
  • Semiconductor equipment parts
  • Aerospace structural components
  • Downhole oil and gas connectors
  • Medical and surgical instrument parts (application-dependent)
  • Food processing machinery components (application-dependent)

PCTFE Common Brands

  • Neoflon®, Kel-F®, Aclon®

PEEK Common Brands

  • TECAPEEK®, SustaPEEK, Ketron®

Characteristic PCTFE PEEK
Broad chemical resistance
Excellent dimensional stability
Good creep resistance
Good low-temperature performance
Near-zero moisture absorption  
Very low gas / vapor permeability  
Oxygen / LOX compatibility  
Cryogenic service (to ~−400°F)  
Radiation resistance  
High tensile and flexural strength  
High stiffness (flexural modulus)  
High continuous service temperature