FEP (flu­o­ri­nated eth­yl­ene propylene)


  • Can be injection-molded and extruded by con­ven­tional meth­ods into rods, tubes and spe­cial profiles
  • Soft mate­r­ial with low ten­sile strength and low wear resistance
  • Heat resis­tant
  • Chem­i­cally inert and insoluble
  • Excel­lent elec­tri­cal properties
  • Mois­ture– and radiation-resistant
  • Trans­par­ent

Com­mon uses

  • Elec­tronic items such as wire cov­er­ing and spaghetti tub­ing lin­ings for pipes in the chem­i­cal indus­try and air­craft wiring
  • Glaz­ing for solar energy collectors
  • Chem­i­cal fluid handling
  • Med­ical tubing
  • Rings
  • Seals and gaskets
  • Microwave insu­la­tion


Mate­r­ial Specifications

ASTM or UL test Prop­erty Value
D792 Den­sity (lb/in3)/(g/cm3) 0.078 (2.15)
D570 Water absorp­tion, 24 hrs (%) <0.01
D638 Ten­sile strength (psi) 3,400
D638 Ten­sile mod­u­lus (psi) -
D638 Ten­sile elon­ga­tion at break (%) 325
D790 Flex­ural strength (psi) No break
D790 Flex­ural mod­u­lus (psi) 85,000
D2176 Fold­ing endurance (cycles) 5–80 x 103
D785 Hard­ness, Shore D D56
D256 Izod notched impact (ft-lb/in) No break
D696 Coef­fi­cient of lin­ear ther­mal expan­sion (x 10–5 in/in/F°/C°) 8.3–10.5
D648 Heat deflec­tion temp (F°/C°) at 264 psi -
D3418 Melt­ing temp (F°/C°) 500/260
- Max oper­at­ing temp (F°/C°) 400/204
C177 Ther­mal con­duc­tiv­ity
(BTU-in/ft2–h– F°)
6 x 104
UL94 Flam­ma­bil­ity rating V-O
D149 Dielec­tric strength (V/mil)
short time, ⅛” thick
D150 Dielec­tric con­stant at 1 MHz 2.1
D150 Dis­si­pa­tion fac­tor at 1 MHz 0.0007
D495 Arc resis­tance (sec) <300
D257 Vol­ume resis­tiv­ity (ohm/cm) at 50% RH 1018

These are typ­i­cal val­ues for ref­er­ence and com­par­i­son only. They should not be used as a basis for design spec­i­fi­ca­tions or qual­ity con­trol. Con­tact us for the man­u­fac­tur­ers’ com­plete mate­r­ial prop­erty datasheets. All val­ues were taken at 73°F (23°C) unless oth­er­wise noted.

Don’t see what you’re look­ing for? Call us at 800–423-2769 or email us at tom@crownplasticsinc.com.