PEEK CNC Machining — Medical, Aerospace & Industrial
PEEK (Polyetheretherketone) delivers performance approaching metals at a fraction of the weight. The choice material for medical implants, aerospace bushings, and semiconductor components where other plastics fail.
Why Machine PEEK?
No other engineering plastic matches PEEK’s combination of temperature resistance, chemical resistance, and mechanical performance.
Extreme Temperature Performance
Continuous service to 260°C, peak to 300°C. PEEK retains mechanical properties at temperatures where most engineering plastics have softened or degraded.
Biocompatible & Sterilizable
Unfilled PEEK is ISO 10993 biocompatible and can be sterilized by autoclave, ETO, gamma, or e-beam — the preferred metal replacement for surgical instruments and implants.
Chemical Resistance
Resistant to almost all organic solvents, hydrocarbons, and acids at elevated temperatures. Unaffected by steam, hydraulic fluids, and aggressive process chemicals.
Metal-Like Precision
Machines to ±0.005mm and holds dimensions in humid environments (0.1% water absorption vs nylon's 2.5%). Direct metal replacement in many structural applications.
PEEK vs Alternatives
Head-to-head against the materials engineers most commonly cross-shop.
PEEK Grades We Machine
Five PEEK grades covering medical, structural, and high-stiffness applications.
| Grade | Tensile (MPa) | Machinability | Best For | Common Uses |
|---|---|---|---|---|
| Unfilled PEEK | 100 MPa | Excellent | Medical, food contact | Implants, seals, valve seats |
| 30% Carbon Fiber PEEK | 200 MPa | Good | Structural, low CTE | Aerospace brackets, structural |
| 30% Glass Fiber PEEK | 160 MPa | Good | Dimensional stability | Bearings, gears, pump parts |
| PEEK-CA30 (Carbon) | 210 MPa | Good | Maximum stiffness | Semiconductor, aerospace |
| PEEK-GF30 (Glass) | 170 MPa | Good | Electrical insulation | Electrical connectors |
PEEK Machining Specifications
Design Tips for PEEK Machining
Anneal PEEK stock at 200°C for 4 hours before machining to relieve internal stresses — eliminates warping during or after machining.
Use sharp tooling and avoid excessive heat buildup — PEEK has low thermal conductivity. Coolant is recommended but air cooling works for light cuts.
Allow 0.1% dimensional change for moisture absorption if the part will see water or humid environments. Unfilled PEEK swells less than filled grades.
Specify 'natural' (beige) vs 'black' PEEK on drawings — black PEEK is often carbon-filled and has different electrical/mechanical properties.
Machined PEEK does not require surface treatment for most applications — the as-machined surface has excellent tribological properties.
Common Applications
Surface Finishes for PEEK
PEEK’s as-machined surface is excellent. These four finishes cover the rest of the typical specs we receive.
As-Machined
Ra 1.6 μm typical. Acceptable for most industrial uses — PEEK's tribological surface is excellent untreated.
Vapor-Polished
Glossy clear finish for medical and optical applications. Ra 0.2 μm achievable on unfilled PEEK.
Glass-Bead Blasted
Uniform matte texture, removes tool marks. Common for cosmetic enclosures and grip surfaces.
Medical Passivation
ISO 13485 cleaning protocol — ultrasonic, DI water rinse, double-bag packaging. Required for implantable parts.
Industries Using Machined PEEK
Where the cost of failure is high enough to justify PEEK’s price tag.
Aerospace
FAR 25.853-compliant cabin parts, fuel-system bushings, electrical connectors. PEEK replaces aluminum where smoke/toxicity is regulated.
Medical
Spinal cages, trauma fixation, surgical instrument bodies. Implant-grade PEEK-OPTIMA is ASTM F2026 qualified.
Semiconductor
Wafer-handling components, ESD-safe carbon-filled grades, end-effectors. Outgassing-low and HF-resistant.
Oil & Gas
Downhole back-up rings, seal carriers, electrical insulators rated for H₂S, CO₂, and supercritical fluids at 200°C+.
Automotive EV
Battery-pack insulators, high-voltage connectors, busbar standoffs. Replaces ceramics in thermal-runaway zones.
Compare with Other Materials
Cross-shop PEEK against our other in-stock engineering materials.
POM (Delrin)
Best machinability of any plastic. Pick for high-volume precision parts where PEEK is overkill.
View detailsAluminum 6061-T6
Higher tensile and conductivity than PEEK. Cheaper, but heavier and not biocompatible.
View detailsStainless 316L
When you need PEEK’s chemical resistance plus metal-level strength and pressure rating.
View detailsReady to Machine PEEK Parts?
Upload your drawings and receive a detailed PEEK machining quote within 24 hours. All grades in stock. Medical NDA available.
