When standard engineering plastics fall short, High Performance PEEK delivers the thermal stability, chemical resistance, and mechanical strength required for critical applications. Kaxite Sealing specializes in machining and supplying High Performance PEEK stock shapes and finished parts, helping engineers across aerospace, oil and gas, medical, semiconductor, and chemical processing industries solve their toughest sealing and wear challenges. This page provides a detailed technical overview of High Performance PEEK, its material parameters, available grades, typical applications, and answers to common questions about working with this exceptional polymer.
High Performance PEEK, or polyetheretherketone, is a semi-crystalline advanced thermoplastic belonging to the polyaryletherketone family. It was developed to bridge the gap between conventional polymers and metals, offering a unique combination of high-temperature resistance, chemical inertness, excellent mechanical properties, and dimensional stability. PEEK retains its mechanical strength and stiffness at temperatures up to 260°C (500°F) in continuous service, which makes it one of the highest-performing unfilled thermoplastics on the market.
Kaxite Sealing supplies High Performance PEEK in both virgin and filled formulations. The material is available in rods, sheets, tubes, and custom machined components. Because of its purity and biocompatibility in select grades, PEEK is also used in medical implants and pharmaceutical processing equipment. Its low outgassing and resistance to high-energy radiation further expand its use in semiconductor and aerospace environments.
High Performance PEEK offers a range of engineering advantages that set it apart from PTFE, nylon, acetal, and other high-performance thermoplastics. The following list summarizes the core benefits that make PEEK a preferred choice for demanding sealing applications.
Kaxite Sealing supplies High Performance PEEK to exacting specifications. The data below reflects typical values for unfilled PEEK rod and sheet stock. Actual values may vary slightly depending on batch, processing method, and test conditions.
| Property | Test Method | Typical Value | Unit |
|---|---|---|---|
| Density | ISO 1183 | 1.30 – 1.32 | g/cm³ |
| Melting Point | ISO 11357 | 343 | °C |
| Glass Transition Temperature | ISO 11357 | 143 | °C |
| Continuous Service Temperature | UL 746B | 260 | °C |
| Short-Term Maximum Temperature | — | 300 | °C |
| Water Absorption at Saturation | ISO 62 | 0.1 – 0.5 | % |
| Rockwell Hardness, M Scale | ISO 2039-2 | 85 – 100 | — |
| Shore D Hardness | ISO 868 | 85 – 90 | — |
| Flammability Rating | UL 94 | V-0 | — |
| Thermal Conductivity at 23°C | ISO 22007 | 0.25 – 0.29 | W/(m·K) |
| Coefficient of Linear Thermal Expansion, 23–150°C | ISO 11359 | 45 – 55 × 10⁻⁶ | 1/K |
| Property | Test Method | Typical Value | Unit |
|---|---|---|---|
| Tensile Strength at Break | ISO 527 | 90 – 100 | MPa |
| Tensile Modulus | ISO 527 | 3.6 – 4.1 | GPa |
| Elongation at Break | ISO 527 | 15 – 30 | % |
| Flexural Strength | ISO 178 | 150 – 170 | MPa |
| Flexural Modulus | ISO 178 | 3.8 – 4.2 | GPa |
| Compressive Strength | ISO 604 | 120 – 130 | MPa |
| Izod Impact Strength, Notched | ISO 180 | 5 – 8 | kJ/m² |
| Poisson’s Ratio | — | 0.38 – 0.40 | — |
| Property | Test Method | Typical Value | Unit |
|---|---|---|---|
| Volume Resistivity | IEC 60093 | 10¹⁶ | Ω·cm |
| Surface Resistivity | IEC 60093 | 10¹⁵ – 10¹⁶ | Ω |
| Dielectric Strength | IEC 60243 | 19 – 24 | kV/mm |
| Dielectric Constant at 1 MHz | IEC 60250 | 3.2 – 3.4 | — |
| Dissipation Factor at 1 MHz | IEC 60250 | 0.003 – 0.005 | — |
Kaxite Sealing offers High Performance PEEK in a range of filled and modified grades to meet specific performance requirements. The table below summarizes the most commonly supplied formulations and their primary advantages.
| Grade | Filler/Modification | Key Advantage | Typical Application |
|---|---|---|---|
| Virgin PEEK | Unfilled | Highest purity and ductility, excellent chemical resistance | Medical components, food processing, semiconductor fixtures |
| PEEK GF30 | 30% glass fiber | Improved stiffness, creep resistance, and dimensional stability at high temperature | Structural insulators, pump housings, electrical connectors |
| PEEK CF30 | 30% carbon fiber | High stiffness, excellent wear resistance, reduced thermal expansion | Bearings, seals, valve seats, compressor components |
| PEEK PVX | Carbon fiber, graphite, PTFE | Optimal bearing and wear performance, low friction | Bushings, wear rings, thrust washers |
| PEEK bearing grade | Carbon fiber, graphite, PTFE | Enhanced load capacity and long service life in rotating equipment | Journal bearings, piston rings, wear pads |
| PEEK medical grade | Unfilled, implantable | ISO 10993 and USP Class VI compliance, radiolucency | Orthopedic implants, spinal cages, dental abutments |
| PEEK antistatic | Carbon nanotube or carbon black | Controlled surface resistivity for ESD-sensitive environments | Semiconductor handling, electronics manufacturing |
One of the defining features of High Performance PEEK is its broad chemical resistance. It withstands prolonged exposure to most organic solvents, acids, bases, and steam. The table below provides a general guide to resistance ratings for common chemical environments. Actual performance depends on temperature, concentration, stress level, and exposure duration.
| Chemical Environment | Concentration | Temperature | Resistance Rating |
|---|---|---|---|
| Sulfuric acid | Up to 60% | 25–80°C | Excellent |
| Hydrochloric acid | Up to 37% | 25–100°C | Excellent |
| Nitric acid | Up to 30% | 25°C | Good |
| Sodium hydroxide | Up to 50% | 25–120°C | Excellent |
| Acetic acid | Up to 80% | 25–100°C | Excellent |
| Acetone | 100% | 25–60°C | Excellent |
| Toluene | 100% | 25–150°C | Excellent |
| Diesel fuel | 100% | 25–120°C | Excellent |
| Steam | — | 200–250°C | Excellent |
| Chlorinated solvents | 100% | 25°C | Good |
| Strong oxidizing acids | Concentrated | Elevated | Limited |
Kaxite Sealing maintains an extensive inventory of High Performance PEEK stock shapes for rapid delivery and custom machining. Standard stock includes extruded rods, compression-molded sheets, and tubes in virgin and filled grades. The table below lists typical size ranges available from Kaxite Sealing. Custom diameters, thicknesses, and lengths can be sourced upon request.
| Stock Shape | Available Size Range | Standard Length/Width | Color |
|---|---|---|---|
| Rod, virgin PEEK | Diameter 5 mm – 200 mm | 1000 mm, 3000 mm | Natural (light tan) |
| Rod, PEEK GF30 | Diameter 6 mm – 150 mm | 1000 mm, 3000 mm | Dark tan |
| Rod, PEEK CF30 | Diameter 10 mm – 120 mm | 1000 mm, 3000 mm | Black |
| Sheet, virgin PEEK | Thickness 5 mm – 80 mm | 500 mm × 500 mm, 1000 mm × 500 mm | Natural |
| Sheet, PEEK GF30 | Thickness 10 mm – 60 mm | 500 mm × 500 mm | Dark tan |
| Sheet, PEEK CF30 | Thickness 10 mm – 60 mm | 500 mm × 500 mm | Black |
| Tube, virgin PEEK | OD 30 mm – 200 mm, wall 5–20 mm | 1000 mm, 3000 mm | Natural |
| Tube, PEEK PVX | OD 30 mm – 150 mm, wall 5–15 mm | 1000 mm | Black |
Kaxite Sealing also provides precision CNC machining for custom High Performance PEEK components. Typical achievable tolerances range from ±0.05 mm for general dimensions to ±0.01 mm for critical sealing surfaces, depending on part geometry and grade selection. Surface finishes down to Ra 0.4 µm are possible with proper tooling and process control.
High Performance PEEK is used across a wide spectrum of industries where reliability under extreme conditions is mandatory. Kaxite Sealing supplies PEEK components for the following applications.
Kaxite Sealing machines High Performance PEEK using CNC turning, milling, and grinding processes. Because PEEK has a relatively low thermal conductivity, machining parameters must be controlled to prevent localized overheating and surface degradation. Recommended practices include using sharp carbide or polycrystalline diamond tooling, moderate cutting speeds, adequate coolant flow, and stress-relieving after rough machining. For tight-tolerance parts, Kaxite Sealing recommends a two-stage machining process that includes a rough cut, an annealing cycle, and a finish cut to relieve internal stresses and achieve dimensional stability.
Annealing of High Performance PEEK is typically performed at 200–220°C for a duration of 2 to 4 hours depending on cross-section thickness. This process reduces residual stress from extrusion or molding and improves machined part accuracy. Kaxite Sealing offers in-house annealing and quality verification for all critical PEEK components.
Kaxite Sealing maintains rigorous quality control procedures for High Performance PEEK materials and finished parts. Every batch of raw material is accompanied by a certificate of analysis confirming mechanical, thermal, and chemical properties. Finished components can be supplied with full dimensional inspection reports, material certifications, and traceability documentation upon request. Kaxite Sealing operates in accordance with ISO 9001 quality management principles and can support customers requiring PPAP, FAIR, or other industry-specific documentation.
High Performance PEEK stands out because it combines continuous temperature resistance up to 260°C, superior chemical resistance, and high mechanical strength in a single thermoplastic. Unlike PTFE, which is soft and creep-prone, PEEK maintains its stiffness and creep resistance at elevated temperatures. Unlike nylon or acetal, PEEK does not absorb significant moisture and retains its dimensional stability in wet or humid environments. This combination of properties allows engineers to replace metal components in many applications, reducing weight, corrosion, and maintenance costs.
The maximum continuous service temperature for unfilled High Performance PEEK is generally rated at 260°C (500°F) according to UL 746B. Short-term excursions to 300°C are possible without immediate material failure, but prolonged exposure above 260°C may lead to thermal oxidative degradation and reduced mechanical properties. Filled grades such as PEEK GF30 and PEEK CF30 may exhibit slightly improved thermal stability and dimensional retention at elevated temperatures, but the upper continuous use limit remains around 260°C for most industrial applications.
Yes. Unfilled virgin High Performance PEEK complies with FDA regulations for repeated food contact in many formulations. Medical-grade PEEK meets USP Class VI and ISO 10993 biocompatibility requirements, making it suitable for short-term and long-term implantable devices. Kaxite Sealing supplies grades specifically designated for food processing and medical applications, with documentation available to support regulatory submissions. It is important to specify the correct grade and avoid filled or pigmented variants unless they are also certified for the intended use.
PTFE offers an extremely low coefficient of friction and excellent chemical resistance, but it lacks the mechanical strength and creep resistance of High Performance PEEK. PTFE cold flows under load and has a continuous service temperature around 260°C, but its wear resistance and load capacity are significantly lower. PEEK, especially filled bearing grades, can withstand much higher PV values and maintains dimensional stability under compressive loads. For high-pressure sealing systems, PEEK is often used as backup rings or anti-extrusion rings behind PTFE seals to prevent extrusion and improve service life.
Kaxite Sealing provides full custom fabrication services for High Performance PEEK parts. Customers can submit 2D drawings, 3D CAD models, or even rough sketches, and the engineering team will review the design for manufacturability, recommend the most suitable PEEK grade, and produce precision-machined components to specification. Kaxite Sealing also offers reverse engineering services for worn or failed parts, material selection guidance, and prototype development before full production runs.
High Performance PEEK is resistant to a wide range of chemicals, but it is not suitable for prolonged exposure to concentrated strong oxidizing acids such as concentrated sulfuric acid, concentrated nitric acid, or oleum. Halogen gases and strong Lewis acids may also degrade PEEK at elevated temperatures. In such environments, Kaxite Sealing recommends evaluating perfluoroelastomers, PCTFE, or other fluoropolymers. For applications involving mixed chemical streams, it is always best to perform compatibility testing under actual service conditions.
High Performance PEEK is a relatively stable thermoplastic and does not require special handling under normal conditions. Kaxite Sealing recommends storing stock shapes in a clean, dry area away from direct sunlight and extreme temperature fluctuations. For precision-machined parts that will be used in high-temperature applications, an annealing step after rough machining is recommended to relieve internal stresses. Finished parts should be protected from sharp impacts and scratches, particularly on sealing surfaces, to maintain dimensional integrity.
Kaxite Sealing can achieve tolerances as tight as ±0.01 mm on critical dimensions for High Performance PEEK components, depending on part geometry, grade, and feature size. Typical production tolerances for seals and bearings are in the range of ±0.02 mm to ±0.05 mm. Because PEEK has a higher coefficient of thermal expansion than metals, measurement temperature should be controlled and specified. For parts that must operate across a wide temperature range, Kaxite Sealing recommends designing with appropriate clearances to account for thermal expansion.
