Guides / Sourcing
PEEK or PTFE: Picking the Right Plastic for a Food or Pharma Part
September 26, 2026
Sources: manufacturer datasheets and published standards. See editorial standards.
PTFE and PEEK both show up on the same food and pharma equipment, often a few centimeters apart, and buyers sometimes assume they are interchangeable because both get called “high performance plastic” on a supplier’s website. They are not interchangeable. Each one earns its place in a different kind of part.
Where each one wins
| Property | PTFE | PEEK |
|---|---|---|
| Friction, unfilled | Among the lowest of any plastic | Moderate, needs a bearing grade blend to compete |
| Chemical range | Broadest of the common plastics, resists nearly everything at low load | Wide, but concentrated sulfuric or oxidising acids attack it, covered in what PEEK resists |
| Strength and stiffness | Low, and it deforms under sustained load | High, holds its shape under load |
| Dimensional stability under pressure | Poor, cold-flows over time even at moderate load | Good, better again in glass or carbon filled grades |
| Continuous service temperature | Roughly 260 degrees C, with low strength retained at that temperature | Roughly 250 degrees C, with far more strength retained |
| Machining to a tight tolerance | Soft and prone to moving after machining | Machines to a tight tolerance and holds it |
| Typical material cost | Lower | Higher |
Why PTFE wins at low load
PTFE’s friction and chemical range are hard to beat when the part carries no significant load: non-stick liners, low-pressure gaskets, coatings on rollers and chutes. Nothing sticks to it, almost nothing attacks it chemically and it costs less than PEEK to buy and often to machine, a difference broken down in what machined PEEK parts cost. None of that changes the fact that it moves under load, so a PTFE part asked to also hold a tight seal geometry under pressure will eventually deform enough to leak or bind, even though the material itself has not failed.
Why PEEK wins where the part carries load
A valve seat, a pump component, a tablet press wear part or anything that has to maintain a precise geometry while also carrying mechanical load or line pressure needs the strength and stiffness that PTFE does not have. PEEK holds its dimensions under load and at temperature well enough that a seal geometry cut into it stays correct for the service life of the part, rather than slowly relaxing the way PTFE does. That combination of strength and dimensional stability is also why PEEK, not PTFE, ends up in structural pump components and fittings, covered in PEEK parts for CIP and SIP process equipment.
Machining is part of the decision too
The two materials do not behave the same way under a cutting tool, and that difference shows up in the finished part before it ever reaches service. PTFE is soft enough that it deflects away from the tool during machining and tends to move slightly after cutting as internal stress relaxes, which makes a tight feature or a fine thread harder to hold consistently across a batch. PEEK cuts more like a hard engineering plastic, holds a sharp edge on a feature, and does not continue moving once it is off the machine. A shop quoting a part with several tight features or a precise seal profile will usually flag PTFE as a risk for exactly this reason, independent of how the two materials compare chemically.
A shortcut for deciding
- Non-stick surface, no meaningful load: PTFE
- Low-pressure static seal, replaced often, cost sensitive: PTFE
- Part carries load, pressure or has to hold a tight seal geometry: PEEK
- Part needs both chemical resistance and structural stiffness at temperature: PEEK
- Concentrated sulfuric acid or similarly aggressive oxidizing chemistry: PTFE or PFA, accepting the load limits that come with it
A wider comparison across PEEK, PTFE, POM and PEI covers the same trade-offs outside the food and pharma context specifically.
Putting the decision on the RFQ
Rather than naming a plastic on the drawing before the shop has seen the full picture, put the actual requirements down: media and concentration, temperature, load or pressure the part carries and whether it has to hold a seal geometry under that load. A shop or engineer reading that list can usually tell you which material fits before guessing from the part name alone.
Not sure which one your part needs? Send the drawing with the load and media conditions and we match you with shops that can advise on both materials.
Frequently asked questions
Is PTFE or PEEK better for a food-grade seal?
For a low-load static seal or gasket, PTFE's chemical range and non-stick surface are usually the better fit at a lower cost. For a seal that also has to hold a precise geometry under sustained pressure, PEEK holds its shape better over time.
Why does PTFE lose tolerance over time and PEEK does not?
PTFE cold-flows, meaning it slowly deforms under sustained load even at room temperature, which is a mechanical property of the polymer rather than a sign of failure. PEEK is far stiffer and does not cold-flow under normal service loads.
Can PEEK replace PTFE anywhere in food processing equipment?
Not everywhere. Where the part needs the lowest possible friction with no load to carry, such as a non-stick liner, PTFE still wins on cost and performance. PEEK is the better choice once the part is structural or has to hold a seal geometry under pressure.
Need a quote for this part?
Send the drawing. We match you with up to 3 shops that cut your PEEK grade and reply within 24 business hours.
Get matched with a PEEK shop