PEEK is usually the stronger choice for bearings and wear parts exposed to higher loads, demanding pressure-velocity conditions and tight dimensional tolerances. PTFE is generally preferred when extremely low friction, broad chemical resistance, soft conformability or reliable dry sliding at moderate load matters most. Filled grades can change this comparison substantially, so material selection should extend beyond virgin PEEK vs virgin PTFE.
Bearing performance depends on the full tribological system. Load, speed, temperature, motion type, lubrication, shaft finish, clearance, environment and duty cycle all influence wear. This guide explains how PEEK and PTFE behave in bushings, plain bearings, thrust washers, guide rings, seal rings and other sliding components.
PEEK and PTFE as Bearing Materials
Polyether ether ketone is a semi-crystalline high-performance thermoplastic with high strength, stiffness, fatigue resistance and dimensional stability. PEEK can be extruded, compression moulded, injection moulded and machined into precision components. Bearing-grade PEEK compounds often include carbon fibre, graphite and PTFE to balance strength, thermal conductivity, friction and wear.
Polytetrafluoroethylene is a fully fluorinated polymer known for very low friction, broad chemical inertness and non-stick behaviour. PTFE bearing components are commonly compression moulded, sintered and machined. Virgin PTFE is soft and prone to creep and relatively high wear under demanding sliding conditions, so filled PTFE is frequently selected for loaded wear parts.
Searches for PEEK vs Teflon or Teflon vs PEEK generally refer to the same material comparison because Teflon is a well-known trademark commonly associated with PTFE. Engineering specifications should still identify the exact PTFE grade, filler system and supplier designation instead of relying on a trade name alone.
Neither material should be chosen from a generic coefficient of friction alone. The mating surface, contact pressure, sliding speed and heat-removal path determine whether the design remains stable.
PEEK vs PTFE: Quick Comparison
| Selection factor | PEEK | PTFE |
|---|---|---|
| Stiffness and strength | High | Low in virgin grade |
| Inherent friction | Low for an engineering thermoplastic | Exceptionally low |
| Virgin-material wear | Generally better under load | Can be high despite low friction |
| Creep resistance | Much better | Requires careful load and clearance design |
| Dimensional stability | Better for precision components | More affected by load and thermal expansion |
| Chemical resistance | Broad, with defined exceptions | Exceptionally broad |
| Continuous high-temperature capability | High and grade dependent | High and grade dependent |
| Machining rigidity | Supports tight features more readily | Requires controlled fixturing and measurement |
| Conformability | Lower | Higher |
These rankings describe general behaviour. Fillers, processing, orientation and the operating environment may reverse a simple virgin-material comparison.
Friction Is Not the Same as Wear
PTFE’s very low coefficient of friction reduces starting force, stick-slip and surface adhesion. These properties make it valuable in lightly loaded dry-running bearings, guide pads, slide plates and sealing elements.
Low friction does not automatically mean low wear. Virgin PTFE can lose material rapidly under certain pressure and speed combinations. Transfer-film formation on the mating surface may improve steady sliding, but shaft condition and operating stability affect the result.
Unfilled PEEK normally has higher friction than PTFE but retains greater mechanical integrity under load. Tribologically modified PEEK compounds can lower friction and wear while preserving much of PEEK’s stiffness. Published supplier examples use combinations of carbon fibre, graphite and PTFE for demanding plain bearings, rollers, seals and guides.
Load Capacity and Contact Pressure
PEEK’s higher compressive strength and modulus support heavier loads and smaller bearing geometries. This advantage matters when space is limited, wall thickness is low or edge loading cannot be eliminated completely.
Virgin PTFE deforms more readily under sustained compression. The bearing may initially run smoothly but lose clearance as creep progresses. Filled compounds can improve compressive behaviour, yet the selected filler must suit the chemical environment and counterface.
Static load and dynamic load should be evaluated separately. Start-stop motion, impact, oscillation and shaft misalignment can create local stresses far above the nominal average pressure.
Pressure-Velocity Limits and Frictional Heat
Pressure-velocity, commonly written as PV, provides a useful screening measure for plain bearings. Contact pressure multiplied by sliding velocity estimates the severity of the operating condition, but it does not predict service life by itself.
Frictional heat can raise the bearing temperature well above the surrounding air or fluid temperature. Higher local temperature reduces stiffness, changes clearance and may accelerate wear. Limited heat removal, continuous rotation and poor counterface contact increase the risk.
PEEK wear grades are often selected for higher PV conditions because they retain strength and resist wear under combined thermal and mechanical stress. Filled PTFE can perform well at lower to moderate PV levels, particularly where low friction and chemical resistance carry greater importance.
Creep, Clearance and Dimensional Stability
Creep is a critical distinction in a PEEK vs PTFE bearing review. PEEK maintains dimensions more effectively under sustained stress. PTFE continues to deform with time, especially at elevated temperature and high contact pressure.
Bearing clearance must accommodate thermal expansion, moisture effects, load deformation and manufacturing tolerance. PTFE normally requires more generous allowance for expansion and creep. PEEK supports tighter running clearance but can still seize if thermal growth and frictional heating are underestimated.
Press-fit bushings need extra care. Excessive interference may close the bore after installation, while insufficient interference can allow rotation in the housing. Prototype measurements should be taken after installation and temperature conditioning.
PEEK vs PTFE Temperature Performance
Both polymers can operate at temperatures beyond many conventional plastics. Selected PEEK references report continuous-use capability up to approximately 260°C, while selected PTFE resin references also identify continuous operation around 260°C.
Equal headline temperatures do not mean equal bearing performance. PEEK retains substantially higher stiffness and strength at elevated temperature. PTFE preserves low friction and chemical inertness but becomes increasingly prone to deformation under load.
The practical PEEK vs PTFE temperature decision therefore depends on load, speed and required dimensional stability, not only the maximum service-temperature figure shown on a data sheet. Grade-specific thermal ageing, compressive strength and wear data should be reviewed at the intended operating temperature.
Frictional heat, thermal cycling and mating-material expansion should be included in the design temperature. The hottest contact zone, rather than the measured ambient temperature, often controls wear and clearance.
Chemical and Environmental Resistance
PTFE offers the broader chemical-resistance envelope and is often chosen for bearings exposed to aggressive acids, bases, solvents or process mixtures. Fillers can introduce restrictions that do not apply to virgin PTFE.
PEEK resists many fuels, oils, steam and industrial chemicals but has defined limitations, including some strong acids and aggressive chemical environments. Grade-specific compatibility should be checked at the operating temperature.
Water, steam, vacuum, radiation and sterilisation can also influence selection. PEEK’s mechanical strength and hydrolysis resistance support many demanding wet or steam applications. PTFE provides very low moisture absorption and excellent vacuum-compatible chemical inertness, subject to outgassing and cleanliness requirements.
Shaft Material and Surface Finish
The counterface is part of the bearing system. Hardness, roughness, coating, runout and corrosion condition influence transfer film, abrasion and heat generation.
Surfaces that are too rough can abrade a soft PTFE bearing. Extremely smooth surfaces may not always support stable transfer-film development, depending on the compound and motion. PEEK wear grades can tolerate demanding contact but may damage a soft or poorly finished shaft.
Final surface requirements should come from testing or grade-specific design data. Generic polished or ground descriptions are insufficient when bearing life is critical.
Dry Running, Lubricated and Contaminated Service
PTFE is naturally suited to low-friction dry sliding and can reduce dependence on external lubricant. Filled PTFE formulations are commonly tailored for better wear and load capacity.
PEEK can also run dry when a suitable bearing grade is selected. PTFE, graphite and carbon-fibre additions can provide solid lubrication, thermal conductivity and reinforcement. Virgin PEEK should not be assumed to match a purpose-designed wear grade.
Lubricants may reduce friction and wear, but compatibility with the polymer and process fluid must be confirmed. Dust, abrasive particles and crystallised process media can dominate wear regardless of the base resin.
Filled PTFE Options
| PTFE formulation | Typical purpose | Important consideration |
|---|---|---|
| Virgin PTFE | Lowest friction, broad chemical resistance and purity | Higher creep and wear under load |
| Glass-filled PTFE | Improved creep and wear performance | Chemical limitations in selected media |
| Carbon-filled PTFE | Improved wear, load response and thermal behaviour | Electrical conductivity and counterface wear may change |
| Graphite-filled PTFE | Improved lubricity and dry-running behaviour | Mechanical reinforcement depends on formulation |
| Bronze-filled PTFE | Higher load capacity and thermal conductivity | Reduced chemical resistance and higher density |
Filler percentage alone does not define performance. Particle type, size, distribution, resin quality, moulding and sintering all affect the finished bearing. JIAFUXIN’s filled fluoropolymer parts section covers drawing-based components and compounded material options.
PEEK Bearing Grades
Virgin PEEK provides strength and dimensional stability but may not deliver the lowest wear rate. Carbon-fibre reinforcement can increase stiffness, load capacity and thermal conductivity. Graphite and PTFE can reduce friction and improve dry-running behaviour.
Commercial bearing-grade formulations often combine several fillers rather than relying on one additive. One published example contains PTFE, graphite and carbon fibre in equal proportions, illustrating how reinforcement and solid lubrication can be balanced in the same compound.
Material designation should identify the exact grade rather than simply “filled PEEK.” Different compounds can have markedly different friction, wear, conductivity, strength and regulatory status.
Machining Bearings and Wear Parts
PEEK’s rigidity makes it easier to hold thin walls, grooves and close concentricity. Machining heat and residual stress still require attention, especially in fibre-reinforced grades. Tool wear can increase when hard fillers are present.
PTFE machines cleanly with sharp tools but deforms under clamping and measuring force. Temperature-controlled inspection, supported fixturing and suitable machining allowance improve consistency. Filled compounds may machine differently from virgin stock.
Finished components can be reviewed through JIAFUXIN’s custom machined parts capability. Drawings should state the installed fit, running clearance, surface finish and inspection condition.
Which Material Fits Each Wear Component?
The same selection principles extend beyond conventional bushings. The phrase PEEK vs PTFE seats commonly describes comparisons involving valve seats, sealing seats and supporting rings exposed to pressure, motion and aggressive media. PEEK generally provides stronger resistance to deformation and extrusion, while PTFE offers lower friction, better conformability and broad chemical compatibility. Pressure, temperature, media, leakage class and mating-surface condition should be evaluated together.
| Component or condition | Typical starting choice | Reason |
|---|---|---|
| High-load plain bearing | Bearing-grade PEEK | Higher strength, stiffness and wear resistance |
| Low-load dry sliding pad | PTFE or filled PTFE | Very low friction and good conformability |
| Precision bushing | PEEK | Better dimensional stability and creep resistance |
| Chemically aggressive guide ring | PTFE compound | Broad chemical resistance with tailored wear properties |
| High-PV thrust washer | Wear-grade PEEK | Retains mechanical integrity under pressure and speed |
| Soft mating surface | PTFE grade selected by testing | Lower hardness may reduce counterface damage |
| High-temperature seal ring | PEEK or filled PTFE | Load, friction, chemistry and clearance determine the choice |
| Food or pharmaceutical equipment | Qualified PEEK or PTFE grade | Documentation and cleanability control approval |
Information Required for Material Selection
- Bearing type, geometry and installed dimensions
- Radial, axial, static, dynamic and impact loads
- Sliding speed, stroke length and motion frequency
- Continuous, intermittent or start-stop duty cycle
- Ambient and estimated contact-zone temperature
- Dry, lubricated, immersed or contaminated conditions
- Shaft material, hardness, coating and surface finish
- Fluid chemistry, concentration and cleaning process
- Required life, allowable wear and clearance change
- Compliance, traceability and inspection requirements
Common Selection Mistakes
- Choosing only by friction coefficient: low friction does not guarantee low wear or adequate load capacity.
- Using virgin-material data for a filled grade: reinforcement changes mechanical, thermal and tribological behaviour.
- Ignoring contact temperature: frictional heating can exceed the measured ambient temperature.
- Calculating PV without reviewing motion: oscillation, start-stop service and edge loading may require different evidence.
- Leaving the counterface unspecified: shaft roughness, hardness and coating affect wear life.
- Using room-temperature clearance at all conditions: thermal expansion and creep can close the running gap.
- Treating every filled PTFE or PEEK compound as equivalent: filler chemistry and production quality matter.
Frequently Asked Questions
Is PEEK better than PTFE for bearings?
PEEK is usually better for high load, higher PV and precision geometry. PTFE is often better when the lowest friction, chemical inertness or conformability is the main requirement. Filled grades and actual operating conditions can change the answer.
Which material has lower friction?
Virgin PTFE generally has lower friction than virgin PEEK. Tribologically modified PEEK can reduce friction while retaining greater stiffness and load capacity.
Why can PTFE wear even though it has low friction?
Friction and wear measure different behaviour. PTFE can slide easily while still losing material under unsuitable pressure, speed, temperature or counterface conditions.
Which material supports heavier loads?
PEEK normally supports heavier loads because it has higher compressive strength, stiffness and creep resistance. Bearing-grade compounds can extend performance further.
Can PEEK bearings run without lubrication?
Yes, when a suitable dry-running or wear grade is selected and the PV, temperature and counterface remain within validated limits. Virgin PEEK should not automatically be treated as a bearing grade.
Which PTFE filler is best for bearings?
No single filler is best for every application. Glass, carbon, graphite, bronze and blended systems address different combinations of load, wear, friction, chemistry and conductivity.
Can PTFE be added to PEEK?
Yes. PTFE is used in some PEEK bearing compounds to reduce friction. Carbon fibre and graphite may also be added to improve reinforcement, thermal behaviour and wear.
Which material holds tighter tolerances?
PEEK generally holds tighter dimensions under load because it is stiffer and more creep resistant. PTFE components require greater attention to fixturing, thermal conditioning and installed clearance.
How should bearing clearance be calculated?
Clearance should account for shaft and housing tolerances, interference fit, thermal expansion, moisture effects, load deformation, creep and expected wear. Grade-specific design data and prototype testing are recommended.
What information should be sent with an enquiry?
Provide the drawing, load, speed, motion, temperature, environment, mating material, lubrication condition, required life, allowable wear and documentation needs. These details support a useful material and tolerance review.
Final Selection
Choose bearing-grade PEEK when load capacity, wear resistance, high PV performance and dimensional stability lead the design. Choose virgin or filled PTFE when very low friction, broad chemical resistance and conformability carry greater importance. Prototype testing remains valuable when duty cycles, counterfaces or contamination are difficult to model.
JIAFUXIN manufactures PEEK and PTFE stock shapes and drawing-based wear components, including bushings, thrust washers, guide rings, seal rings and slide parts. Send the drawing and operating conditions through the JIAFUXIN contact page for material and manufacturing review.
