PEEK vs PTFE Teflon: Complete Engineering Comparison (2026) — Temperature, Strength, Cost

Which Material Should You Choose?Choose PEEK (Polyetheretherketone) if:Structural load-bearing components at high temperaturegears, bearings, brackets, downhole toolsapplications requiring both chemical resistance and mechanical strengthChoose...

PEEK and PTFE are both elite high-performance polymers rated for 260°C continuous service, but they occupy fundamentally different positions in the engineering design space. PEEK is a structural thermoplastic with 4× the tensile strength of PTFE, excellent fatigue resistance, and full melt-processability via injection molding. PTFE offers the lowest coefficient of friction of any solid (0.04) and the broadest chemical resistance of any polymer, but cannot be injection molded and has negligible mechanical strength. The choice between them is determined by whether the application demands structural load-bearing (PEEK) or friction/chemical barrier performance (PTFE).

Property Comparison

Tensile Strength: PEEK: 100 MPa / PTFE: 25 MPa. PEEK is 4× stronger — this is the single most important differentiator. PTFE's low strength limits it to compressive-load or self-supporting liner applications. Flexural Modulus: PEEK: 4.1 GPa / PTFE: 0.5 GPa. PEEK is 8× stiffer, enabling structural components with predictable deflection. PTFE is so flexible that it cold-flows (creeps) under sustained load — a PTFE gasket under bolt load will relax over time, requiring spring-energized designs. Coefficient of Friction: PEEK: 0.20-0.35 (unfilled) / PTFE: 0.04-0.10. PTFE's near-zero friction makes it the gold standard for dynamic seals and bearing surfaces. PEEK bearing-grade formulations (CF/PTFE/graphite filled) reduce friction to ~0.10, bridging the gap. Chemical Resistance: PTFE is inert to virtually every chemical including aqua regia, molten alkali, and all organic solvents — no polymer matches PTFE's chemical universality. PEEK resists most chemicals but is attacked by concentrated sulfuric acid and some halogens. For 95% of chemical environments, both are excellent; for the most aggressive chemistry, PTFE is the only option. Processability: PEEK is injection-moldable (360-400°C melt, 160-200°C mold), enabling complex net-shape parts in high volume. PTFE cannot be melt-processed — it decomposes before flowing. PTFE parts are made by sintering compressed powder or ram-extruding, limiting geometries and increasing cost for complex shapes. Wear Resistance: Unfilled PTFE has poor wear resistance (high PV limit but rapid material loss). PEEK bearing-grade (e.g., Victrex PEEK 450FC30) offers 100× the wear life of unfilled PTFE in boundary-lubricated conditions. Cost: PEEK: $80-200/kg / PTFE: $25-60/kg. PTFE is 30-50% the cost of PEEK per kg, but PTFE's inability to be injection molded means piece-part costs can be higher for complex geometries.

Decision Matrix

Choose PEEK When: (1) The part must bear tensile, flexural, or fatigue loads — structural brackets, gears, bearing cages, compressor valve plates; (2) Complex geometry requires injection molding — PTFE cannot achieve net-shape for intricate features; (3) Long-term creep resistance under load is required — PTFE cold-flows, PEEK does not; (4) Dynamic sealing with structural backup is needed — PEEK spring-energized seal with PTFE lip is a common hybrid; (5) Tribological performance under load is needed — PEEK bearing-grade outwears unfilled PTFE by 100×. Choose PTFE When: (1) The application is a seal, gasket, or liner where chemical inertness and low friction dominate; (2) Universal chemical resistance is required — PTFE handles chemicals that attack PEEK; (3) The part geometry is simple enough for sintering or machining from stock; (4) Non-structural chemical barrier applications — pipe linings, valve seats, pump diaphragms; (5) Low friction is the primary design driver — PTFE's 0.04 coefficient of friction cannot be matched by any PEEK formulation.

Comparison at a Glance

Equivalents & Cross-References

Related Diagnostics & Materials

References & Industry Standards

• ASTM International. Standard Specifications for Engineering Plastics & Thermoplastics. astm.org
• UL Prospector. Plastics & Elastomers Material Database. ulprospector.com
• MatWeb. Material Property Data for Engineering Thermoplastics. matweb.com
• ISO 1043. Plastics — Symbols and Abbreviated Terms. iso.org