PEEK vs PTFE (Teflon)
PEEK and PTFE (Teflon) are both high-performance polymers, but they solve opposite problems: one is a load-bearing structural plastic, the other a low-friction, chemically inert lining material. The right pick depends almost entirely on whether your part has to carry load or just survive contact.
The verdict
Choose PEEK when the part must bear mechanical load, hold tight tolerances, or run hot under stress — it is a true structural engineering plastic. Choose PTFE (Teflon) when you need maximum chemical inertness, the lowest friction, or non-stick sealing, and the part carries little or no load. In short: PEEK for strength and stiffness, PTFE for slip and inertness.
Side-by-side data
| Property | PEEK | PTFE (Teflon) |
|---|---|---|
| Category | Engineering Plastic | Engineering Plastic |
| Density (g/cm³) | 1.32 | 2.17 |
| Tensile strength (MPa) | 100 | 25 |
| Yield strength (MPa) | 97 | 15 |
| Elongation (%) | 45 | 300 |
| Hardness | R126 | D55 |
| Max service temp (°C) | 250 | 260 |
| Machinability | ●●●●● | ●●●●● |
| Corrosion resistance | ●●●●● | ●●●●● |
| Relative cost | ●●●●● | ●●●●● |
| Thermal cond. (W/m·K) | 0.25 | 0.25 |
| Typically used for | High-temp, chemical & medical-grade parts | Chemical-resistant, non-stick, low friction |
Which should you choose?
Choose PEEK if…
- The part is structural — gears, bushings, manifolds, brackets, or fasteners that must carry real mechanical or fatigue load.
- You need tight, stable tolerances; PEEK is rigid, low-creep, and machines like a metal substitute.
- Service is hot and stressed at once (continuous use near 250 C) where PTFE would deform.
- You want a metal-replacement that can be glass- or carbon-filled for extra stiffness and wear resistance.
- Steam, radiation, or repeated autoclave cycles are involved (medical, aerospace, semiconductor).
Choose PTFE (Teflon) if…
- You need near-universal chemical inertness — aggressive acids, bases, and solvents that attack almost everything else.
- Low friction or non-stick behavior is the goal: seals, gaskets, bearing pads, slide surfaces, and liners.
- The part is unloaded or lightly loaded — PTFE creeps (cold-flows) badly under sustained stress.
- You need a soft, conformable sealing material or a tank/pipe lining rather than a structural component.
- Dielectric performance and very low moisture absorption matter, as in cable insulation.
Key differences that matter
- PEEK is a structural plastic; PTFE is functionally a sealing/lining material — they are not interchangeable on a load-bearing part.
- PTFE has the lower friction and broader chemical resistance, but it cold-flows (creeps) under sustained load and cannot hold precision tolerances over time.
- PEEK keeps stiffness and creep resistance hot and under stress, where PTFE softens and deforms; PTFE's headline temperature rating assumes little or no load.
- Machinability differs in kind: PEEK cuts crisp and dimensionally stable like an engineering thermoplastic, while soft PTFE deforms and smears, making tight tolerances hard.
- Neither is weldable or bondable in the metal sense — PTFE is notoriously hard to glue without surface etching, and PEEK is typically joined mechanically or by specialized fusion, not adhesives.
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Open the Material SelectorGet a Quote →Frequently asked questions
Is PEEK stronger than PTFE (Teflon)?
Yes, substantially. PEEK is a rigid, load-bearing structural plastic with high tensile and fatigue strength, while PTFE is soft and prone to cold-flow under sustained load. For any part that must carry mechanical stress, PEEK is the clear choice.
Which is cheaper, PEEK or PTFE?
PTFE is generally cheaper per pound and easier to source. PEEK is one of the most expensive commodity-grade engineering polymers. But compare installed cost: a thin PTFE liner versus a machined structural PEEK part are different jobs, so price alone rarely decides it.
Can you machine PEEK and PTFE?
Both are machinable, but differently. PEEK machines like a tough engineering plastic and holds tight, stable tolerances. PTFE is soft and tends to deform, smear, and spring back, so precision features are harder and it needs sharp tooling and light cuts.
Which has better chemical and temperature resistance?
PTFE wins on raw chemical inertness — it resists nearly all acids, bases, and solvents. On temperature it depends on load: PTFE tolerates high heat unloaded, but PEEK holds its strength and shape far better when hot and mechanically stressed at the same time.
Can PTFE or PEEK be welded or glued?
Not easily. PTFE is famously non-stick, so bonding requires aggressive surface etching (sodium treatment) and is rarely structural. PEEK is usually joined mechanically or by specialized fusion/ultrasonic methods rather than adhesives. If you need to weld or glue, plan for it early.
Property values are typical/nominal figures for early-stage guidance only and vary by temper, grade, supplier and heat treatment. Confirm critical specifications against a certified datasheet or with an mfgiq engineer before production.