Polytetrafluoroethylene (PTFE)
PTFE is a fluoroplastic (fluorine-based thermoplastic). It can have a fairly high density among thermoplastics. In addition, it can have a moderately high ductility and a fairly low tensile strength.
The properties of PTFE include three common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare PTFE to: fluoroplastics (top), all thermoplastics (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Compressive (Crushing) Strength
6.9 to 24 MPa 1.0 to 3.5 x 103 psi
Elongation at Break
75 to 300 %
Flexural Modulus
0.4 to 1.3 GPa 0.058 to 0.19 x 106 psi
Flexural Strength
13 to 50 MPa 1.9 to 7.3 x 103 psi
Tensile Strength: Ultimate (UTS)
13 to 25 MPa 1.9 to 3.6 x 103 psi
Thermal Properties
Heat Deflection Temperature At 1.82 MPa (264 psi)
66 to 70 °C 150 to 160 °F
Maximum Temperature: Mechanical
260 to 270 °C 500 to 510 °F
Melting Onset (Solidus)
330 to 340 °C 630 to 640 °F
Thermal Conductivity
0.24 to 0.65 W/m-K 0.14 to 0.38 BTU/h-ft-°F
Thermal Expansion
110 to 120 µm/m-K
Electrical Properties
Dielectric Constant (Relative Permittivity) At 1 MHz
2.1 to 2.4
Electrical Dissipation At 1 MHz
0.00017 to 0.050
Electrical Resistivity Order of Magnitude
2.0 to 18 10x Ω-m
Otherwise Unclassified Properties
Density
2.1 to 2.3 g/cm3 130 to 140 lb/ft3
Limiting Oxygen Index (LOI)
90 %
Water Absorption After 24 Hours
0.0093 to 0.050 %
Common Calculations
Strength to Weight: Axial
1.7 to 3.2 points
Strength to Weight: Bending
5.7 to 8.7 points
Followup Questions
Further Reading
Fluoroplastics: Volume 2 - Melt Processable Fluoropolymers, Sina Ebnesajjad, 2003
Reinforced Plastics Durability, Geoffrey Pritchard (editor), 1999
SPI Plastics Engineering Handbook of the Society of the Plastics Industry, Inc., 5th ed., Michael L. Berins (editor), 2000
Modern Plastics Handbook, Charles A. Harper (editor), 1999
Plastics Materials, 7th ed., J. A. Brydson, 1999