PTFE (Unfilled)
PTFE (Polytetrafluoroethylene) resin was invented by DuPont in 1938. The extraordinary characteristics of PTFE make it the ideal choice in a wide range of products and applications. PTFE boasts the highest chemical resistance and the lowest coefficient of friction of all polymers available. It can withstand a wide range of temperatures, from cryogenic to 550 degrees F. PTFE is extremely corrosion resistant, especially to acids, and harsh inorganic and organic chemicals, it retains its properties even after extended periods in water.
As a plane bearing material, PTFE in its unfilled form does not perform well as it has very little creep strength. However, when modified with filler materials like Glass, Ceramic, Bronze, Moly or Polyimide; it becomes an excellent bearing with Limiting PV values of up to 10,000. It is easily machined with conventional metal working equipment and is available in rod, sheet, tubing as well as custom tubular bar.
| Specification | Test | Value | Units |
| Specific Gravity, 73°F | D792 | 2.22 | – |
| Tensile Strength @ Yield, 73°F | D638 | 3,000 | psi |
| Tensile Modulus of Elasticity, 73°F | D638 | psi | |
| Tensile Elongation (at break), 73°F | D638 | 270 | % |
| Flexural Strength, 73°F | D790 | 20,000 | psi |
| Flexural Modulus of Elasticity | D790 | psi | |
| Shear Strength, 73°F | D732 | psi | |
| Compressive Strength – Ultimate | 50 | psi | |
| Compressive Strength at 2% Deformation | D695 | 100 | psi |
| Compressive Strength at 10% Deformation | D695 | 500 | psi |
| Deformation Under Load | % | ||
| Compressive Modulus of Elasticity, 73°F | D695 | ||
| Compressive Strength ⊥ to Laminate (Modulus) | psi | ||
| Compressive Strength ⊥ to Laminate (Yield) | 100 | psi | |
| Compressive Strength ⊥ to Laminate (Ultimate) | 100 | psi | |
| Hardness, Durometer (Shore “D” scale) | D2240 | D60 | |
| Hardness, Rockwell (Scale as noted) | D785 | Rockwell M | |
| Izod Impact, Notched @ 73°F | D256 Type A | ft.lbs/in. of notch | |
| Coefficient of Friction (Dry vs Steel) Static | PTM 55007 | 0.15 | |
| Coefficient of Friction (Dry vs Steel) Dynamic | PTM 55007 | 0.10 | |
| Maximum Static Bearing Load (P) | PTM 55007 | 50 | psi |
| Maximum Unlubricated No Load Bearing Velocity (V) | PTM 55007 | 200 | ft/minute |
| Maximum Limiting PV (Unlubricated) | PTM 55007 | 1,000 | psi x ft/min. |
| Wear Factor “K” x 10-10 | PTM 55010 | Cubic in.-min/ft.lbs.hr | |
| Sand Wheel Wear/Abrasion Test | 20 | UHMW=100 | |
| Minimum Mating Surface Hardness | 20 | Rockwell (Brinnell) | |
| Coefficient of Linear Thermal Expansion | E-831 (TMA) | 6.0 | in/in/°F x 10-5 |
| Coefficient of Thermal Expansion // to Laminates | E-831 (TMA) | 6.0 | in/in/°F x 10-5 |
| Coefficient of Thermal Expansion I to Laminates | E-831 (TMA) | 6.0 | in/in/°F x 10-5 |
| Softening Point | °F | ||
| Heat Deflection Temperature 264 psi | D648 | °F | |
| Embrittlement Temperature | Cryogenic | °F Min. | |
| Continuous Service Temperature in Air | 550 | °F Max. | |
| Short Term Service Temperature | 550 | °F Max. | |
| Tg-Glass Transition (Amorphous) | D3418 | 635 | °F |
| Melting Point (Crystalline) Peak | D3418 | °F | |
| Thermal Conductivity | F433 | BTU-in/(hr/ft2°F) | |
| Dielectric Strength Short Term | D149 | 200 | Volts/mil |
| Volume Resistivity | D257 | ohm/cm | |
| Surface Resistivity | D257 | ohm/cm | |
| Dielectric Constant, 106 Hz | D150 | ||
| Dissipation Factor, 106 Hz | D150 | ||
| Flammability @ 3.1mm(1/8 in.) UL94 | UL94 | V-0 | |
| Arc Resistance | seconds | ||
| Water Absorption, Immersion 24 Hours | D570 (2) | Nil | % |
| Water Absorption, Immersion Saturation | D570 (2) | Nil | % |
| Machinability Rating | 7 | 1=easy, 10=difficult | |
| Tubing Diameter Availability (Off the Shelf) | .50 | 36 | inches |
| Sheet Thickness Availability (Off the Shelf) | .030 | 4.0 | inches |
| Characteristics / Attributes | Superior Chemical Resistance / Self Lubricating / Inert / Lowest Coefficient of Friction |
