PTFE O-Ring
Kaxite Sealing’s PTFE O-Ring offers superior chemical resistance and durability for demanding industrial applications, perfect for engineers seeking reliable sealing solutions. Its unique design ensures leak-free performance, enhancing safety and efficiency in harsh environments.
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Product Description
Made in Ningbo, China
Kaxite has been producing PTFE O-rings in Ningbo since 2015. We make them in virgin PTFE and in the filled grades most plants actually ask for — glass, carbon, graphite, bronze and PEEK-modified. The seals hold up from -200°C to +260°C and shrug off almost every industrial chemical except molten alkali metals and elemental fluorine. If your current O-rings keep failing in acid, solvent or steam service, this is usually the material that stops the leak for good.
Most of our buyers are maintenance engineers, plant procurement teams and distributors who need a reliable second source. We ship to more than 100 countries, and we're used to working from a drawing or even just a groove dimension and a description of the medium.
The Numbers Buyers Ask For First
These are the commercial terms we quote most often. If you're comparing suppliers, use them as a baseline — but do send us your actual drawing, because compound and quantity change the numbers.
MOQ
100 pcs per size for stock sizes; 500 pcs for custom molds and filled compounds
Lead Time
7–15 working days for stock, 15–25 working days for custom production
Price Range
Roughly USD 0.05–0.50 for small standard sizes; USD 10–20 for large or PEEK-filled parts
Payment
30% T/T deposit, balance against B/L copy. L/C at sight above USD 30,000
Shipping
FOB Ningbo or Shanghai. CIF, CFR and DDP quoted on request
Samples
5–10 pcs free for evaluation. You cover the courier
Packing
PE bag inside, carton outside, pallet for sea freight. Private label available
OEM / ODM
Drawing-to-part, custom compound, laser marking, your brand on the box
Quotation
Formal quote back within 24 hours of receiving your drawing or application details
Why Buyers Keep Coming Back
You Talk to the Factory
We're a manufacturer, not a trading company. When you send a drawing, it goes to the production team, not to a middleman who then marks up the price. On most standard sizes that saves buyers 15–20% compared with buying through a reseller.
The Second Batch Matches the First
Inconsistency between shipments is the number one complaint we hear about other suppliers. Every lot we ship goes through dimensional inspection and comes with a material certificate. If you need independent verification, we can arrange SGS or Intertek inspection before the goods leave.
One Supplier, All the Compounds
If you buy virgin PTFE from one vendor and filled grades from another, you're managing two lead times, two quality systems, and two sets of paperwork. We stock and mold all the common compounds, so a mixed order ships together.
Stock Sizes Ship Fast
We keep the common AS568 and DIN 3771 groove sizes on the shelf. That means repeat orders go out in a week to ten days instead of a month. Custom molds take longer, but we'll tell you exactly how long before you commit.
Food, Medical and EU Buyers Covered
FDA 21 CFR 177.1550 grades for food and medical service, and RoHS / REACH compliant compounds for the EU. These aren't special-order items with six-week lead times — we keep them in the standard production flow.
Answers From Someone Who Knows the Part
Send us the medium, temperature and pressure, and we'll tell you which compound and hardness to use, and whether the groove you have in mind will actually work with PTFE. You get a real recommendation, not a copy-paste from a datasheet.
How We Keep Quality Consistent
The risk with O-rings is never the first order — it's the fifth. Here's the four-stage check every batch goes through before it's packed.
Incoming resin: density, tensile strength and elongation are verified before the material goes into production.
In-process: inner diameter, outer diameter and cross-section are measured against the drawing every 50 pieces.
Final inspection: 100% visual and dimensional check, with photos kept on file for two years.
Paperwork: material certificate to EN 10204 3.1, dimensional report and hardness test report ship with every order.
If something's wrong: we replace or credit the part, and come back with a root-cause analysis within 48 hours. No arguing, no runaround.
PTFE, FKM, EPDM or NBR — Which One Fits Your Line?
If you already know you need PTFE, skip this section. If you're still comparing materials, the table below is the fastest way to rule out the wrong one.
| Property | PTFE | FKM (Viton) | EPDM | NBR |
|---|---|---|---|---|
| Temperature range | -200 to +260°C | -20 to +200°C | -50 to +150°C | -40 to +120°C |
| Acid resistance | Excellent | Good | Fair | Poor |
| Solvent resistance | Excellent | Good | Poor | Fair |
| Steam resistance | Excellent | Fair | Good | Poor |
| Elastic recovery | Low | High | High | High |
| Relative cost | High | Medium | Low | Low |
| Typical use | Chemical, food, semiconductor | Oil, fuel, automotive | Water, steam, outdoor | Oil, fuel, general |
Short version: pick PTFE when the chemical or the temperature is the hard part of the job. Pick FKM when you need elasticity and oil resistance more than chemical breadth. EPDM is for water and steam. NBR is the cheap general-purpose choice for oil and fuel.
What to Tell Us So We Can Quote You Right
Most delays in quoting come from missing information. If you can send these five things with your inquiry, you'll usually have a price back the same day.
Medium — the chemical, gas or fluid the part will contact.
Temperature — both the normal running temperature and any peaks.
Pressure — working pressure in MPa or bar.
Dimensions — inner diameter, outer diameter or cross-section, plus the groove standard if you have one.
Quantity — annual usage or the trial order size, so we can quote the right price tier.
Don't have all five? Send what you have. We can recommend the missing values based on similar applications we've done before.
Where These Seals Are Used
A quick look at the industries and equipment that most often call for PTFE O-rings.
Chemical plants: pumps, valves, reactors, heat exchangers and flange joints handling acids, bases and solvents.
Semiconductor fabs: wet benches, CMP tools, wafer cleaning and etch equipment where contamination is not an option.
Food and beverage: fillers, mixers, homogenizers and CIP systems, using FDA-compliant grades.
Medical and lab: analytical instruments, IV sets, dialysis equipment and sterilization systems.
Oil and gas: downhole tools, wellhead equipment and refinery valves, usually with filled compounds.
Analytical labs: HPLC, GC, mass spec and vacuum systems that need a chemically inert seal.
Technical Data
Values below are typical for the three grades we ship most. If you need a specific property tested, tell us and we'll include the result in your quotation.
| Property | Unit | Virgin PTFE | Glass-filled | Carbon / Graphite-filled |
|---|---|---|---|---|
| Hardness | Shore D | 55–65 | 60–70 | 60–70 |
| Tensile strength, min | MPa | 16 | 16 | 16 |
| Elongation, min | % | 60 | 60 | 80 |
| Compressibility | % | 50–60 | 50–60 | 60–75 |
| Recovery | % | >85 | >85 | >70 |
| Permanent set | % | <10 | <10 | <20 |
| Temperature limit | °C | -20 to +250 | -20 to +200 | -50 to +200 |
| Pressure limit | MPa | 0–35 | ||
Common Sizes We Keep in Stock
These cross-sections and inside diameters cover most of what customers order. If yours isn't here, it's not a problem — we mold custom sizes all the time.
| Section Dia (mm) | Nominal ID (mm) | Section Dia (mm) | Nominal ID (mm) |
|---|---|---|---|
| 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 |
Non-standard sizes, filled compounds, private-label orders — all fine. Send the drawing and we'll confirm within a day.
Questions We Get Asked Most
What are PTFE O-rings actually used for?
Mostly static sealing in equipment where rubber won't survive — chemical pumps, valves, reactors, flanges and analytical instruments. They're also used in semiconductor tools and food processing, where the material needs to be chemically inert and easy to clean. Typical service is -200°C to +260°C at up to 35 MPa.
How wide is the temperature range?
Continuous service from -200°C to +260°C, with brief excursions to around 300°C. The filled grades trade a bit of the high end for better compression set and wear resistance. If you're running above 260°C continuously, we'd normally steer you toward PEEK or a spring-energized seal instead.
Will they hold up against strong acids and solvents?
Yes, with two exceptions — molten alkali metals and elemental fluorine. Everything else in normal industrial service is fine, including concentrated sulfuric and nitric acid, caustic soda, hydrocarbons and steam. That's the main reason buyers choose PTFE over FKM or NBR in the first place.
PTFE or FKM — which should I pick?
If chemical resistance and temperature range are the hard part, go PTFE. If the application is oil, fuel or automotive and you need good elasticity at lower cost, FKM is usually the better fit. One thing to know about PTFE: its elastic recovery is low, so it's best in static seals or paired with a spring energizer for dynamic use.
Solid PTFE or encapsulated — what's the difference?
Solid PTFE is PTFE all the way through, which gives the best chemical resistance but the least elasticity. An encapsulated O-ring has a silicone or FKM core with a thin PTFE jacket, so it installs more easily and recovers better. Solid PTFE for aggressive static seals, encapsulated for dynamic or tight-tolerance grooves.
Can they be used in moving applications?
Yes, with limits. Low-speed rotary pumps, valves and reciprocating rods are fine — typically under 0.5 m/s surface speed. For anything faster or more demanding, use a filled compound (carbon, graphite or bronze) plus a spring energizer or backup ring. Solid virgin PTFE alone won't maintain contact pressure under dynamic load.
Can you make custom sizes and hardnesses?
Yes. Any ID from 20 mm to 2000 mm, cross-sections from 1.8 mm to 12 mm, hardness from 60 to 90 Shore A. Virgin PTFE or filled — glass, carbon, graphite, bronze, PEEK. Tolerances follow DIN 3771 or AS568, or your drawing if you have something specific.
What's the MOQ and how long does production take?
100 pieces for standard sizes, 500 for custom molds and filled compounds. Stock sizes ship in 7–15 working days; custom runs take 15–25, depending on whether we need a new mold. Samples of 5–10 pieces are available for evaluation before you commit to a full order.
What do the parts cost?
Small standard sizes in virgin PTFE run around USD 0.05–0.50 each. Large diameters above 500 mm, or PEEK-filled compounds, can reach USD 10–20. It really depends on the size, compound and volume — send a drawing and we'll give you a firm number within 24 hours.
Do you supply FDA, RoHS or REACH compliant grades?
Yes. FDA 21 CFR 177.1550 for food and medical use, RoHS and REACH compliant compounds for the EU. Material certs and third-party reports from SGS or Intertek are available on request — just tell us at the inquiry stage so we include them in the quote.
How do I install one without damaging it?
Warm it to 40–60°C first, which makes the material noticeably more flexible. Stretch it gently over the groove — don't roll it over sharp edges or threads. PTFE doesn't stretch much, so avoid going past 10% over the ID. A light PTFE-compatible grease helps it seat. On large diameters, a split installation jig saves a lot of grief.
Why do PTFE O-rings leak, and how do I stop it?
Almost always one of two things: low elastic recovery or high compression set. The fix is usually to switch to a filled compound, increase squeeze to 20–30%, confirm the groove matches DIN 3771 or AS568, and add a spring energizer or backup ring on dynamic seals. Groove width within ±0.05 mm and surface finish below Ra 0.8 μm make a real difference too.
Get a Quote
Send Us the Application — We'll Send Back a Recommendation
Tell us the medium, temperature, pressure and quantity. If you have a drawing, attach it. Our engineers will pick the right compound and hardness, confirm the groove will work, and get a formal quotation back to you within 24 hours. Small trial orders and larger wholesale quantities are both welcome.
Hot Tags: PTFE O-Ring Supplier, Custom PTFE O-Ring Manufacturer, PTFE O-Ring for Sale
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