Kaxite PTFE O-Rings are precision-machined from virgin or filled polytetrafluoroethylene, delivering exceptional sealing performance where standard rubber O-rings fail. With outstanding chemical inertness, a wide operating temperature range from -200°C to +260°C (short-term up to +300°C), and an extremely low coefficient of friction, PTFE O-rings are the ideal choice for aggressive media, high-purity systems, and high-temperature applications.
Available in three standard compounds: Grade A – Virgin PTFE (highest chemical resistance, lowest friction), Grade B – 25% Glass-Filled PTFE (improved compressive strength and dimensional stability), and Grade C – 25% Carbon-Filled PTFE (enhanced thermal conductivity and wear resistance). Custom sizes, compounds, and colors are available on request.
Typical applications: Chemical processing, petrochemical, oil & gas, pharmaceutical, food & beverage, semiconductor, aerospace, automotive, and marine industries.
| Grade | Filler | Best For | Avoid In |
|---|---|---|---|
| A | Virgin PTFE | Food, pharmaceutical, semiconductor, ultra-pure chemicals, cryogenic service | High-load dynamic seals, abrasive media |
| B | 25% Glass Fiber | Hydraulic & pneumatic sealing, chemical pumps, valves, moderate load | Hydrofluoric acid, hot alkalis, high-purity applications |
| C | 25% Carbon / Graphite | High-pressure hydraulic seals, high-speed dynamic service, heat transfer | Food contact, pharmaceutical, electrical insulation |
We can produce other non-standard PTFE O-rings and custom compounds. Contact our engineers for a tailored recommendation.
| Property | Unit | Compound Grade | |||
|---|---|---|---|---|---|
| A | B | C | |||
| Normal Conditions | Hardness | Shore D | 55-65 | 60-70 | 60-70 |
| Tensile Strength, min | MPa | 25 | 18 | 18 | |
| Elongation, min | % | 300 | 200 | 150 | |
| Compressive Strength (1% deformation) | MPa | 10 | 16 | 16 | |
| Coefficient of Friction | - | 0.04-0.10 | 0.10-0.20 | 0.10-0.20 | |
| Permanent Set | % | <10 | <10 | <10 | |
| 230°C ×24h hot air ageing | Change of hardness, max. | Shore D | ±2 | ±2 | ±2 |
| Change of tensile strength, max. | % | -5 | -5 | -5 | |
| Change of elongation, max. | % | -10 | -10 | -10 | |
| Compression Permanent Set | 175°C ×70h | % | ≤10 | ≤10 | ≤10 |
| Colour | - | - | white | grey | black |
| Applications | Temperature Limits | °C | -200 to +260 | -200 to +260 | -200 to +260 |
| Pressure Limits | MPa | 0-35 | |||
| Chemically resistant to nearly all industrial chemicals, solvents, acids, and bases, except molten alkali metals, elemental fluorine, and some fluorinating agents. Suitable for water, steam, hydrocarbons, hydrogen, chlorine, strong caustics, and moderate acids. | |||||
| Section Diameter | Nominal Inside Diameter | Section Diameter | Nominal Inside Diameter |
|---|---|---|---|
| 1.80±0.10 | 20±0.10-300±1.60 | 6.00±0.13 | 80±0.80-400±2.00 |
| 2.60±0.10 | 20±0.15-300±1.60 | 6.30±0.14 | 80±0.80-400±2.00 |
| 3.55±0.10 | 25±0.15-300±1.60 | 7.00±0.14 | 100±0.65-1000±4.00 |
| 4.00±0.10 | 40±0.20-300±1.60 | 8.00±0.16 | 110±1.00-2000±4.00 |
| 4.60±0.10 | 40±0.20-300±1.60 | 10.00±0.18 | 200±1.50-2000±6.00 |
| 5.00±0.10 | 40±0.25-400±1.80 | 12.00±0.18 | ≥400±1.50-6.00 |
| 5.30±0.13 | 60±0.30-400±1.80 | 14.00±0.18 | ≥400±1.50-6.00 |
| 5.50±0.13 | 60±0.30-400±1.80 | 16.00±0.18 | ≥400±1.50-6.00 |
| 5.70±0.13 | 60±0.30-400±2.00 |
Don't see your size? Request a custom quotation – we machine non-standard dimensions to your drawings.
Kaxite PTFE O-rings operate continuously from -200°C to +260°C and can withstand short-term excursions up to +300°C. For continuous service above +260°C, PEEK or other high-temperature polymers are recommended.
For maximum chemical resistance and purity, choose Grade A (Virgin PTFE). For moderate chemical exposure with higher mechanical load, Grade B (Glass-Filled) is a good balance. Grade C (Carbon-Filled) offers the best wear resistance and thermal conductivity for high-pressure dynamic seals but is not recommended for food or pharmaceutical contact. Need help? Ask our engineers →
Yes. Virgin PTFE O-rings are widely used in vacuum systems down to 10⁻⁶ Torr. For high-vacuum or ultra-high-vacuum service, use Grade A with a proper backup ring and low-outgassing surface finish.
PTFE is incompatible with molten alkali metals such as molten sodium and potassium, elemental fluorine at elevated temperature and pressure, and some fluorinating agents such as chlorine trifluoride. For these media, alternative materials such as PCTFE or Kalrez should be considered.
Yes. Kaxite produces custom PTFE O-rings to your drawings or samples, including non-standard section diameters, inner diameters, tolerances, and filled compounds such as graphite, bronze, MoS₂, and PEEK. Send us your specifications for a quick quotation.
Standard sizes are available from small trial quantities. Custom sizes typically require a minimum order of 50-100 pieces depending on dimensions. Standard lead time is 7-15 working days; expedited service is available for urgent projects.
Send us your application details — operating temperature, pressure, media, and dimensions — and our engineering team will recommend the optimal PTFE grade and size for your project. Quotation within 24 hours.
Address
No 432 Zhenhai Middle Road, Luotuo Street, Zhenhai District, Ningbo City, Zhejiang China
