China Top PEEK Mechanical Properties for Global Buyers
China has become an important source of PEEK components, compounds, and semi-finished materials. Global buyers need more than a high tensile-strength number. They must examine the complete peek mechanical properties profile, including tensile modulus, elongation, impact resistance, compressive strength, creep, fatigue, and wear behavior.
Professor Vikas Mittal, a recognized polymer materials researcher, has stated, “High-performance polymers succeed when processing, structure, and application are considered together.” This principle matters during supplier evaluation. A PEEK rod may appear excellent on paper, yet machining direction, annealing, filler content, and molding history can change its performance. Carbon-fiber PEEK often offers higher stiffness and lower thermal expansion. Glass-fiber grades may provide balanced reinforcement. Unfilled PEEK can deliver better ductility and sliding behavior.
The numbers need context. PEEK melts near 343°C and has a glass-transition temperature near 143°C. These values do not guarantee performance inside every pump, bearing, seal, or medical instrument. Continuous load can still create creep. Repeated movement can still cause wear. Humidity is usually less damaging than with many engineering plastics, but it should not be ignored.
Reliable Chinese suppliers should provide material certificates, batch traceability, processing guidance, and test methods. Buyers should compare ISO or ASTM results under similar temperatures, specimen shapes, and conditioning periods. A datasheet is not a guarantee. It is only a starting point. Even experienced teams sometimes overlook machining stress or filler dispersion. That weakness deserves attention before mass production.
PEEK Fundamentals and Key Mechanical Property Terms
China Top PEEK Mechanical Properties for Global Buyers
PEEK fundamentals begin with its polymer structure and testing condition. Unfilled PEEK typically shows tensile strength near 90–100 MPa and tensile modulus around 3.5–4.0 GPa. These ranges appear in ISO 527 datasets within the CAMPUS plastics database. ASTM D638 reports may produce slightly different values because specimen shape, speed, and conditioning vary. Heat matters. At 150°C, stiffness can fall sharply compared with room-temperature results.
Tensile strength measures resistance before breaking. Tensile modulus describes stiffness, not toughness. Elongation at break shows how far the material stretches. Typical unfilled grades may reach 20–30% elongation, while reinforced grades often show higher stiffness but lower elongation. Compressive strength is commonly reported near 100–125 MPa, although the exact result depends on loading speed and sample geometry. ISO 178 flexural data often places unfilled PEEK near 3.5–4.0 GPa in flexural modulus. These figures are useful, but not universal. I would not approve a design from one datasheet alone.
Tips: Ask for test standards, conditioning details, batch records, and full stress–strain curves. Check whether values describe unfilled, glass-filled, or carbon-filled PEEK. Compare data at the actual service temperature. A small reporting gap can become a large design risk. Also, some published values look precise, yet laboratory variation remains real.
Typical mechanical properties of unfilled PEEK at room temperature. Values are representative reference figures; actual results vary with grade, processing method, specimen geometry, and test standard.
How China’s Top PEEK Grades Compare Mechanically
Chinese PEEK grades increasingly match global mechanical benchmarks, but comparisons require identical test conditions. The 2024 CAMPUS Plastics Database reports unfilled PEEK tensile strength near 90–100 MPa and tensile modulus around 3.5–4.0 GPa, measured under ISO 527 methods. These values suit precision parts, seals, and sliding components exposed to heat.
Reinforced grades show clearer differences. Data compiled from ISO 527 and ISO 178 test reports indicate that 30% glass-fiber PEEK commonly reaches 140–170 MPa tensile strength and 7–9 GPa flexural modulus. Carbon-fiber grades often provide approximately 160–210 MPa tensile strength, with lower density and better dimensional stability. However, fiber orientation can change results sharply. A molded specimen is not always representative of a machined part.
Wear performance needs separate attention. Tribology reports from ASTM D3702 testing show that filled PEEK can reduce friction and wear, but counterface material, load, and lubrication alter the outcome. This is where many comparisons become too confident. Moisture conditioning, molding temperature, and annealing also affect modulus and elongation. China’s leading grades can perform very well, yet buyers should request full ISO or ASTM test conditions, not only headline numbers. Small data gaps remain important.
PEEK Strength, Stiffness, Wear Resistance, and Temperature Performance
China Top PEEK Mechanical Properties for Global Buyers
PEEK combines high strength, stiffness, wear resistance, and heat stability in demanding components. Unfilled grades often provide tensile strength near 90–100 MPa and tensile modulus around 3.5–4.0 GPa. Reinforced grades can improve stiffness, dimensional stability, and load capacity. However, fiber orientation matters. A molded part may perform differently along and across its flow direction. Test both directions when the part carries a structural load.
Wear performance depends on more than a low friction value. Contact pressure, sliding speed, surface finish, temperature, and lubrication can change results sharply. In practical sleeve testing, a smooth metal shaft and controlled alignment often reduce wear. Poor alignment can create a narrow, overheated wear track. That detail is easy to miss. Material formulations with suitable fillers may reduce wear, but they can increase shaft damage or reduce impact toughness. The trade-off deserves measurement.
PEEK can support continuous use near 250°C in properly designed applications, while its glass transition temperature is about 143°C and melting point is close to 343°C. These numbers are useful, not absolute design permissions. Repeated heating and cooling may cause stress, creep, or dimensional drift. I have seen thermal assumptions look convincing until fasteners loosen after cycling. Measure parts under real load, temperature, and moisture conditions. Short laboratory tests may not represent years of service.
China Top PEEK Mechanical Properties for Global Buyers - PEEK Strength, Stiffness, Wear Resistance, and Temperature Performance
Typical property ranges for unfilled PEEK resin in injection-molded or machined form. Actual values vary with grade, processing conditions, specimen geometry, moisture, temperature, and test method.
| Property Dimension |
Typical Value |
Unit |
Typical Test Reference / Condition |
Engineering Relevance |
| Density |
1.30–1.32 |
g/cm³ |
ISO 1183 / ASTM D792 |
Useful for weight calculations and material selection. |
| Tensile Strength |
90–100 |
MPa |
ISO 527 / ASTM D638, room temperature |
Indicates resistance to tensile loading before yielding or failure. |
| Tensile Modulus |
3.5–4.0 |
GPa |
ISO 527 / ASTM D638 |
Represents stiffness and resistance to elastic deformation. |
| Elongation at Break |
20–50 |
% |
ISO 527 / ASTM D638 |
Shows ductility and capacity to accommodate strain. |
| Flexural Strength |
140–170 |
MPa |
ISO 178 / ASTM D790 |
Important for beams, brackets, clips, and other bending-loaded parts. |
| Flexural Modulus |
3.5–4.2 |
GPa |
ISO 178 / ASTM D790 |
Helps predict deflection under bending loads. |
| Compressive Strength |
100–125 |
MPa |
ASTM D695, room temperature |
Relevant to bushings, thrust washers, seals, and load-bearing components. |
| Notched Impact Strength |
5–10 |
kJ/m² |
ISO 180 / ASTM D256, method and notch dependent |
Indicates resistance to sudden impact and crack initiation. |
| Coefficient of Friction |
0.20–0.35 |
Dimensionless |
Pin-on-disc; dry sliding, counterface and load dependent |
Supports low-friction designs, but application testing is essential. |
| Specific Wear Rate |
10−7–10−6 |
mm³/N·m |
Dry sliding laboratory range; speed, load, surface, and lubrication dependent |
Lower values generally indicate better wear resistance. |
| Glass Transition Temperature (Tg) |
143–150 |
°C |
DSC / ISO 11357 |
Marks the transition affecting stiffness and dimensional stability. |
| Melting Temperature (Tm) |
343–345 |
°C |
DSC / ISO 11357 |
Defines the processing window for melt fabrication. |
| Continuous Use Temperature |
250–260 |
°C |
Long-term service estimate; environment and stress dependent |
Demonstrates suitability for demanding high-temperature applications. |
| Heat Deflection Temperature |
150–160 |
°C |
ISO 75 / ASTM D648, 1.8 MPa load |
Indicates short-term dimensional resistance under elevated temperature and load. |
Note: Wear performance is highly application-specific. For critical components, verify the selected material under the actual load, speed, temperature, counterface, lubrication, and environmental conditions.
Testing Standards for Evaluating PEEK Mechanical Properties
China Top PEEK Mechanical Properties for Global Buyers
Testing Standards for Evaluating PEEK Mechanical Properties
A reliable PEEK evaluation starts with controlled specimen preparation. Tensile strength and elongation are commonly measured under ISO 527 or ASTM D638. Flexural performance is tested under ISO 178 or ASTM D790. Impact resistance may follow ISO 179 or ASTM D256, depending on the buyer’s specification.
Conditioning matters. Test specimens should be stabilized under a defined temperature and humidity, often following ISO 291. A laboratory should record temperature, humidity, specimen thickness, machining direction, and crosshead speed. These details affect the results. Small changes can alter elongation and impact values.
Record every detail.
Compression testing may use ISO 604 or ASTM D695, while hardness can be checked using suitable Shore or Rockwell methods. For high-temperature applications, testing should reflect the intended service temperature rather than room temperature alone. PEEK can behave differently after annealing, sterilization, or prolonged heat exposure.
A common weakness is comparing numbers from different standards. That comparison can be misleading. Even identical PEEK grades may show different results because of fiber content, mold flow, surface finish, or specimen geometry. I would request the original test report, calibration date, failure mode, and batch information before approving a supplier. One missed detail can weaken an otherwise professional assessment.
How Global Buyers Can Select the Right China PEEK Grade
China Top PEEK Mechanical Properties for Global Buyers
Selecting the right China PEEK grade starts with the application, not the supplier’s catalog. Unfilled PEEK commonly shows tensile strength near 90–100 MPa under ISO 527 testing. Its continuous-use temperature is often rated around 250°C. These values vary with molding conditions, specimen geometry, and test speed. Check the test report carefully.
For sliding parts, choose a grade with controlled friction and wear data. Carbon-fiber or glass-fiber reinforcement can raise stiffness and reduce thermal expansion. However, reinforcement may increase brittleness and affect mating surfaces. For example, reported flexural modulus can rise from roughly 3.5 GPa unfilled to above 10 GPa in reinforced grades. Ask for ISO 178 results, not general marketing claims. Also review ASTM D570 water absorption data when dimensional stability matters.
Production consistency deserves equal attention. PlasticsEurope’s 2024 industry report recorded 413.8 million tonnes of global plastics production in 2023. PEEK is only a small specialist segment, so public market estimates differ considerably. That limitation matters. Request three recent batch reports, melt-flow data, ash content, and resin traceability. Confirm whether values represent pellets or molded samples. A certificate without lot identification is weak evidence. Trial parts should undergo actual load, temperature, chemical, and cycle testing. One overlooked issue is machining stress; a strong grade can still warp after cutting.
