Views: 220 Author: plastic-material Publish Time: 2025-12-05 Origin: Site
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● Key Properties of PEEK Material
● What Is PEEK Material Used For?
● How PEEK Is Made: Composition & Manufacturing
● How to Choose the Right PEEK Grade
>> Get PEEK Material from the Factory
PEEK (polyetheretherketone) is a semi-crystalline, high-performance engineering thermoplastic from the PAEK family. It combines a melting point of 343°C (649°F), continuous service temperature of 260°C (500°F), tensile strength of about 100 MPa in its unfilled form, and outstanding chemical resistance —all while remaining machinable and lightweight (density 1.30 g/cm3, roughly 1/6 of steel). Below is the complete picture: what PEEK is made of, how it performs, and which grade fits your application.
PEEK stands for polyetheretherketone, a member of the polyaryletherketone (PAEK) family. Its backbone alternates ether groups (C–O–C) and ketone groups (C=O) on aromatic benzene rings — the rigid ketone-linked rings deliver heat resistance and strength, while the flexible ether links keep the polymer tough and melt-processable. The result is a rare balance: thermoplastic workability with performance close to thermosets and metals.
PEEK is semi-crystalline, with a typical crystallinity of 30~35%. The crystalline regions give it chemical resistance and fatigue strength; the amorphous regions give it toughness. This is also why processing history matters — annealing and cooling rates change the crystalline structure and therefore the final properties of the finished part.
The tables below show typical values across the five most common PEEK grades, tested to ISO standards at 23°C. Full grade-by-grade data is available in our PEEK material selection guide >>
| Item (Standard) | Unfilled | GF30 | CF30 | Bearing Grade | ESD |
|---|---|---|---|---|---|
| Tensile strength (ISO 527) | 100 MPa | 175 MPa | 250 MPa | 140 MPa | 210 MPa |
| Elongation at break (ISO 527) | 45% | 2.7% | 1.7% | 2.2% | 2.1% |
| Flexural strength (ISO 178) | 165 MPa | 265 MPa | 380 MPa | 230 MPa | 310 MPa |
| Flexural modulus (ISO 178) | 4.1 GPa | 11 GPa | 23 GPa | 11.5 GPa | 16 GPa |
| Charpy impact, notched (ISO 179/eA) | 7 kJ/m2 | 8 kJ/m2 | 9 kJ/m2 | 5 kJ/m2 | 7 kJ/m2 |
| Item (Standard) | Unfilled | GF30 | CF30 | Bearing Grade | ESD |
|---|---|---|---|---|---|
| Melting point (ISO 11357) | 343°C / 649°F (all grades) | ||||
| Glass transition, Tg (ISO 11357) | 143°C / 289°F (all grades) | ||||
| HDT (ISO 75 A/B) | 152°C | 315°C | 336°C | 293°C | 293°C |
| Continuous service temp. | 260°C / 500°F — short-term peaks to 300°C / 572°F (all grades) | ||||
| Thermal expansion (ASTM D696) | 45 ppm/K | 18 ppm/K | 5 ppm/K | 20 ppm/K | 8 ppm/K |
| Thermal conductivity (ISO 22007-4) | 0.29 W/(m·K) | 0.32 W/(m·K) | 0.95 W/(m·K) | 0.86 W/(m·K) | 0.95 W/(m·K) |
| Item (Standard) | Unfilled | GF30 | CF30 | Bearing Grade | ESD |
|---|---|---|---|---|---|
| Density (ISO 1183) | 1.30 g/cm3 | 1.51 g/cm3 | 1.40 g/cm3 | 1.44 g/cm3 | 1.37 g/cm3 |
| Water absorption, 24h (ISO 62-1) | 0.07% | 0.04% | 0.04% | 0.04% | 0.05% |
| Shore D hardness (ISO 868) | 85 | 88 | 88 | 83 | 86 |
| Volume resistivity (IEC 60093) | 1016 Ω·cm | 1016 Ω·cm | 105 Ω·cm | 1010 Ω·cm | 106~109 Ω·cm |
PEEK earns its place where cheaper plastics fail and metals add weight or corrosion risk. Typical applications by industry:
Aerospace: brackets, cable conduits, and interior components that replace aluminum at 60% weight reduction — with flame, smoke, and toxicity (FST) compliance.
Semiconductor: CMP rings, wafer carriers, and vacuum chucking parts where low particle generation and plasma resistance matter.
Oil & gas: seal rings, valve seats, and compressor parts rated for high pressure, steam, and aggressive media downhole.
Medical: implantable unfilled PEEK (spine cages, trauma plates) thanks to bone-like stiffness and radiolucency, plus sterilizable instrument components.
Automotive & industrial: thrust washers, piston rings, gears, and bearings —; bearing-grade PEEK runs dry or boundary-lubricated at high PV values.
Electronics: ESD grades for wafer handling and SMD trays; unfilled PEEK for high-temperature connectors and insulators (dielectric strength 20 kV/mm).
Highest-performing melt-processable thermoplastic: 260°C continuous service with short-term peaks to 300°C.
Broad chemical resistance: withstands nearly all solvents, fuels, and oils; only concentrated sulfuric acid and a few aggressive reagents attack it.
Hydrolysis & steam resistance: retains properties after thousands of hours in superheated steam above 200°C —; critical for medical and food sterilization.
Inherent flame retardancy: UL 94 V-0 at low thickness without additives, with low smoke and toxic gas emission.
Wear & fatigue performance: bearing grades reach PV values no other unfilled thermoplastic matches, running dry against steel.
Machinable and recyclable: thermoplastic scrap and chips can be reground and reprocessed, unlike thermosets (for stock shapes, unfilled PEEK absorbs only 0.07% water in 24h, so dimensional stability is excellent).
Cost: at roughly $60-90 per kg for Chinese granules (and more for imported resin), PEEK costs 20–50× more than commodity plastics. Design only where the performance justifies it.
High processing temperature: melt processing at 360–400°C requires special equipment and mold temperatures above Tg (143°C) for semi-crystalline parts.
Not UV-stable by default: natural PEEK degrades under prolonged UV exposure unless carbon-filled or coated.
Annealing sensitivity: un-annealed machined parts can gain crystallinity and shift dimensions in service above Tg —; stress-relief annealing is part of the process, not an option.
PEEK is synthesized by step-growth nucleophilic aromatic substitution: the two monomers are hydroquinone and 4,4'-difluorobenzophenone (DFBP), reacted in diphenyl sulfone solvent with sodium carbonate as the base at around 300–320°C. Each coupling step forms an ether linkage, building the alternating ether–ketone backbone. PEEK contains no bisphenol A —; a common misconception worth correcting.
After polymerization and purification, the PEEK resin powder is melted, compounded (with glass fiber, carbon fiber, graphite/PTFE, or anti-static agents for modified grades), and pelletized. From there it takes two routes:
Stock shapes: extruded or compression-molded into sheets, rods, and tubes, followed by stress-relief annealing before CNC machining.
Injection molding: melted at 360–400°C and injected into molds for high-volume parts; mold temperature control (170~200°C) sets the final crystallinity.
| PEEK Grade | Best For | Watch Out For |
|---|---|---|
| Virgin (unfilled) | Chemical resistance, ductility, purity —seals, medical components | Lower stiffness (HDT 152°C) than reinforced grades |
| GF30 (30% glass) | High stiffness & dimensional stability at lower cost than CF —structural parts | Abrasive to tools—not for sliding contact |
| CF30 (30% carbon) | Highest strength & stiffness, low CLTE (15 ppm/K)— precision structural parts | Electrically conductive —unsuitable for insulation |
| Bearing grade (CF + graphite + PTFE) | Dry-running bushings, wear rings, high-PV sliding parts | Lower impact strength |
| ESD / anti-static | Semiconductor handling, electronics trays (10⁶–10⁹ Ω·cm) | Resistivity window must be verified per batch |
Still unsure? Send us your working temperature, load, and media —; our PEEK material selection guide >> covers the full decision tree, or contact our engineers directly for a material recommendation.
PRES is a factory-direct PEEK manufacturer in Dongguan, China —; stock shapes from 1mm to 120mm thick, all five grades above, 1-piece MOQ and cut-to-size service.
