PTFE
The most chemically resistant polymer, very low friction
Typical values for the temper in the title
PTFE (polytetrafluoroethylene, "Teflon") resists almost all chemicals, has the lowest friction coefficient of solid materials, and works over a very wide temperature range (from about -200 to about 260 °C). It is also an excellent electrical insulator, and almost nothing sticks to it.
Its weaknesses: it is soft and weak (about 25 MPa), and creeps under constant load ("cold flow"). Because of its very high melt viscosity it is not injection molded, but compression molded and sintered. It is used for seals and gaskets, bearings and sliding surfaces, chemical piping and linings, and cable insulation.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 25 MPa | |
| Elongation A | 200% | |
| Modulus of elasticity E | 0.5 GPa | |
| Density ρ | 2.20 g/cm³ | |
| Max continuous service temperature | 260°C | |
| Machinability | 60% | relative rating in the site database |
Structure and family
| Feature | Value | Meaning |
|---|---|---|
| Type | semi-crystalline fluoropolymer | chemical resistance and low friction |
| Tm melting | about 327 °C | very high viscosity: not injection molded |
| Service range | about -200 to 260 °C |
Typical values per producer data sheets.
Grades and versions
In engineering polymers, the choice is between an unfilled grade, filled grades (glass or carbon fiber) and special grades (bearing, medical, food). Filler strongly changes strength, stiffness and expansion.
| Version | Properties | When to choose it |
|---|---|---|
| Virgin | soft, maximum chemical resistance | seals, food and medical equipment |
| Glass filled | lower creep and wear | seals and bearings |
| Bronze filled | thermal conductivity, wear resistance | bearings |
| Carbon or graphite filled | low wear, slightly conductive | piston rings |
Applications
- Seals and gaskets
- Bearings and sliding surfaces
- Chemical piping and linings
- Cable insulation
- Food and medical equipment
Fabrication
Machining
Easy, but the material is soft and smears. Very sharp tools and gentle clamping, and for precise dimensions let the part stabilize at temperature.
Cold flow
Under constant load it slowly deforms. In seals and bearings limit pressure, or use filled grades.
Safety
Heated above the service temperature it releases harmful fumes. Do not overheat or burn scraps.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| PVDF | 50 MPa | Hot Gas / Ultrasonic | PVDF: strong and weldable, less resistant · material page |
| UHMWPE | 35 MPa | Not possible | UHMWPE: low friction and very low wear, cheap · material page |
| POM (Acetal) | 70 MPa | Ultrasonic | POM: strong and stable, low friction · material page |
Common mistakes
Using PTFE under high constant pressure
It creeps. Use a filled grade or another material.
Using room-temperature dimensions for cold or hot use
Expansion is high, with a sharp dimensional change near room temperature.
Trying to bond it untreated
Almost nothing sticks to it. A special chemical etch is needed.
Equivalents, standards and supply
| ASTM | D4895 |
|---|---|
| Standards | ASTM D4894 / ASTM D4895 |
| Forms | plate · rod · pipe · tape |
| Producers | Chemours Teflon · Daikin · AGC |
Learn more
Values are typical for an unfilled grade (unless stated otherwise) and for comparison only. In polymers, properties depend on grade, filler, temperature, moisture and load duration. For design, rely on the producer data sheet for the specific grade. Sources: ASTM classification standards (D8033, D5205, D5204, D6394, D4067 and others), producer data sheets, and the METAL HUB materials database.
Updated: October 31, 2026