PEEK CLASSIX Implant Grade Properties — Complete Engineering Data Sheet (2026)
Tensile data verified against MatWeb.com database & manufacturer datasheets · Last updated July 2026
Published: 2026-06-08
PEEK implant grades are a distinct category of PEEK polymer specifically manufactured under ISO 13485 quality systems for long-term implantable medical devices. The base polymer chemistry is the same as industrial PEEK, but the manufacturing...
PEEK implant grades are a distinct category of PEEK polymer specifically manufactured under ISO 13485 quality systems for long-term implantable medical devices. The base polymer chemistry is the same as industrial PEEK, but the manufacturing process, quality control, and documentation are entirely different. Implant-grade PEEK undergoes: (a) more stringent monomer/polymer purification to reduce extractables, (b) lot-level biocompatibility testing per ISO 10993, (c) full traceability from resin lot to finished device, and (d) packaging and handling under cleanroom conditions. The three major suppliers are Invibio (PEEK-OPTIMA — the market leader), Victrex (PEEK CLASSIX), and Solvay (Zeniva PEEK).
Clinical applications include: spinal fusion cages (the largest single application by volume — PEEK's radiolucency allows post-operative CT/MRI imaging of fusion progress, impossible with titanium cages), dental implants and abutments, orthopedic fracture fixation plates, cranial reconstruction implants, and cardiovascular device components. PEEK's elastic modulus (3-4 GPa) is closer to cortical bone (15-20 GPa) than titanium (110 GPa) — this reduces stress shielding, where a stiff implant carries all the load and the surrounding bone resorbs from disuse. The osseointegration of PEEK is inferior to titanium unless surface-modified (plasma-sprayed titanium coating, hydroxyapatite coating, or sulfonation treatment).
Recommended Applications
PEEK CLASSIX Implant Grade is commonly specified for:
⚠ Not Recommended For
PEEK CLASSIX Implant Grade is not recommended for:
- Food contact without FDA-grade certification (Classix or 450G compliant grades only)
- Outdoor UV exposure without UV-stabilized grade (unfilled PEEK yellows and embrittles under UV)
- High-impact shock loading below -60°C (becomes brittle; consider PAI or PI instead)
Selection & Application Guide
PEEK is the material of choice when your application demands continuous service above 250°C, outstanding chemical resistance across a wide pH range, and high mechanical strength simultaneously. Choose PEEK over PTFE when load-bearing capacity matters, over Ultem when temperatures exceed 180°C, and over PPS when toughness and elongation are critical. PEEK justifies its premium cost ($80-200/kg) in aerospace, oil & gas downhole, and medical implant applications where failure is not an option.
Real-World Applications
PEEK's radiolucency (invisible on X-ray/CT) combined with bone-matching modulus makes it the standard for interbody spinal fusion devices per ASTM F2026.
PEEK withstands H2S, amine inhibitors, and 200°C+ temperatures at depth — replacing metal components that corrode in aggressive well environments.
PEEK's low particle generation, chemical resistance to strong acids, and dimensional stability at elevated temperatures make it ideal for cleanroom wafer handling.
Carbon-fiber reinforced PEEK (CA30) provides wear resistance and thermal stability for high-temperature dynamic sealing in automotive transmissions.
Processing & Cost Considerations
Manufacturing Tips
- Melt temperature must be 380-400°C with mold temperature 160-200°C — standard injection molding machines cannot process PEEK. You need a high-temperature package with ceramic heater bands and oil-heated mold system.
- Drying is critical: PEEK is hygroscopic and must be dried at 150-160°C for 3-4 hours to reach moisture content below 0.02%. Processing wet PEEK causes hydrolysis, brown discoloration, and loss of mechanical properties.
- Mold temperature controls crystallinity: below 150°C produces amorphous parts (transparent amber, lower strength); 160-180°C yields optimal semi-crystalline structure (30-35% crystallinity, opaque tan).
PEEK raw material costs $80-200/kg depending on grade (unfilled 450G is $150-200/kg, CF-reinforced $180-250/kg). Machine premium adds 30-50% for high-temperature capability. Oil-heated mold systems cost $20,000-50,000 additional. Total molded part cost runs 5-10x higher than nylon or polycarbonate. Optimize by minimizing wall thickness to reduce material usage, using unfilled grade when reinforcement isn't needed, and considering PPS as a lower-cost alternative when service temperature stays below 200°C.
Technical Properties
| Density | 1.30 g/cm³ |
|---|---|
| Tensile Strength | 100 MPa |
| Melting Point | 343 °C |
| Shrinkage Rate | 1.1% |
| Flexural Modulus | 4.0 GPa |
| Hdt | 160 °C at 1.82 MPa |
Engineering Tool: Shrinkage & Cost Estimator
Calculate part weight, mold cavity dimensions accounting for shrinkage, and material cost — all locally in your browser.
Equivalents & Cross-References
| Equivalent / Alternate | Action |
|---|---|
| Invibio PEEK-OPTIMA | |
| Victrex PEEK CLASSIX | |
| Solvay Zeniva PEEK |
Frequently Asked Questions
Is implant-grade PEEK chemically different from industrial PEEK?
The base polymer chemistry is identical. The difference is in: manufacturing quality (ISO 13485), purification (lower extractables), biocompatibility testing (ISO 10993 for every lot), traceability, and cleanroom handling. Industrial PEEK from the same reactor may be chemically identical but lacks the regulatory documentation and lot-level testing required for implantable devices. Never substitute industrial PEEK for implant-grade in a medical device — the regulatory and liability consequences are severe.
Does PEEK integrate with bone (osseointegration)?
Unmodified PEEK is bioinert — bone does not bond to it directly. A fibrous tissue layer forms between the implant and bone, which is mechanically weaker than direct bone-implant contact. This is PEEK's primary limitation compared to titanium. Surface modification techniques (plasma-sprayed titanium, hydroxyapatite coating, sulfonation) are used to promote osseointegration. When comparing PEEK vs. titanium for a load-bearing implant, consider whether osseointegration or radiolucency is the higher priority.
Can PEEK be used for FDA-compliant food contact applications?
Yes. Unfilled PEEK complies with FDA 21 CFR 177.2415 for repeated food contact. It also meets USP Class VI and ISO 10993 biocompatibility standards for medical devices. Always verify the specific grade with the manufacturer — colorants and fillers may affect compliance.
Is PEEK resistant to steam autoclaving?
Yes. PEEK withstands repeated autoclave cycles at 134°C and 2 bar pressure — one of the few thermoplastics suitable for this sterilization method. It resists hydrolysis in steam environments, making it standard for reusable surgical instruments and dental components.
What is the difference between PEEK and PEKK?
PEKK (polyetherketoneketone) has a higher glass transition temperature (165°C vs 143°C for PEEK) and can be processed at lower temperatures due to its lower crystallization rate. PEKK offers comparable chemical resistance but different crystallization behavior — it can be quenched to an amorphous state more easily than PEEK. PEKK costs 20-40% more than PEEK.
Can PEEK be machined instead of injection molded?
Yes. PEEK is readily machined on CNC equipment using carbide or diamond tooling. Machined PEEK parts are common for prototyping and low-volume aerospace components. However, machining generates significant material waste (PEEK costs $150+/kg), so injection molding is more economical for volumes above 500-1000 pieces.
Does PEEK outgas in vacuum environments?
PEEK has exceptionally low outgassing characteristics — TML (Total Mass Loss) below 1.0% and CVCM (Collected Volatile Condensable Materials) below 0.1% per ASTM E595. This makes PEEK suitable for satellite and space applications where vacuum compatibility is required.
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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