Reinforced PEEK – GF30, CF30 and bearing grade
PEEK with glass fiber, carbon fiber or a sliding filler package (CF/PTFE/graphite)
Fillers take PEEK to another level: glass fiber (GF30) increases stiffness and stability; carbon fiber (CF30) gives even higher stiffness, better heat conduction and low wear; the bearing grade (carbon fiber, PTFE and graphite, such as TECAPEEK PVX and Ketron HPV) is designed to slide under load and at high speed without lubrication. This is the group of plastics with the highest PV limit.
Designations and equivalents
| System | Designation |
|---|---|
| Abbreviation (ISO 1043) | PEEK GF30 / CF30 / bearing grade |
| Trade names | TECAPEEK GF30 natural (Ensinger); Ketron GF30 PEEK (MCAM); TECAPEEK CF30 black (Ensinger); Ketron CA30 PEEK (MCAM); TECAPEEK PVX black (Ensinger); Ketron HPV PEEK (MCAM) |
Standards by product form
| Form | Standard |
|---|---|
| Rod, sheet and tube | Stock-shape manufacturer's specification |
| Machined part to drawing | ISO 2768 tolerance or as per drawing |
Composition and filler
Nominal composition by mass; the bearing grade varies by manufacturer
| Component | Content |
|---|---|
| PEEK | ≈ 70% |
| GF30: glass fiber | 30% |
| CF30: carbon fiber | 30% |
| Bearing grade: carbon fiber + PTFE + graphite | ≈ 30% in total (10% each, depending on the manufacturer) |
Mechanical properties
Typical values from the stock-shape manufacturer's catalog, 23 °C (GF30, CF30, bearing grade); ISO/ASTM methods as per the source
| Property | Value |
|---|---|
| Tensile strength | GF30: 113 MPa · CF30: 112 MPa · bearing grade: 84 MPa |
| Modulus of elasticity (tensile) | GF30: 6,300 MPa · CF30: 6,000 MPa · bearing grade: 5,500 MPa |
| Elongation at break | GF30: 5% · CF30: 10% · bearing grade: 3% |
| Compressive strength | GF30: 120 MPa · CF30: 111 MPa · bearing grade: 102 MPa |
| Hardness | GF30: Shore D 90 · CF30: Shore D 90 · bearing grade: Shore D 87 |
| Notched impact | GF30: 3 kJ/m² · CF30: 5 kJ/m² · bearing grade: 3 kJ/m² |
Typical physical and thermal properties
| Property | Value |
|---|---|
| Density | GF30: 1.53 g/cm³ · CF30: 1.38 g/cm³ · bearing grade: 1.44 g/cm³ |
| Maximum continuous service temperature | 260 °C |
| Maximum short-term temperature | 300 °C |
| Minimum service temperature | -20 °C |
| HDT (1.8 MPa) | GF30: 316 °C · CF30: 270 °C · bearing grade: 195 °C |
| Melting point or glass transition | 341 °C |
| Linear thermal expansion | GF30: 40 µm/m·K · CF30: 40 µm/m·K · bearing grade: 30 µm/m·K |
| Thermal conductivity | GF30: 0.35 W/m·K · CF30: 0.66 W/m·K · bearing grade: 0.82 W/m·K |
| Water absorption (24 h) | 0.02-0.03% |
| Water absorption (saturation) | GF30: 0.35% · CF30: 0.3% · bearing grade: 0.3% |
| Dielectric strength | GF30: 36 kV/mm |
| Flammability (UL 94) | V-0 |
Calculate the weight of Reinforced PEEK – GF30, CF30 and bearing grade bar, plate or pipe →
Friction, wear and PV limit
| Property | Value |
|---|---|
| Dynamic coefficient of friction against steel | GF30: 0.3 (dynamic, ASTM D3702, 40 psi (0.28 MPa), 50 ft/min (0.25 m/s)) · CF30: 0.13 (dynamic, ASTM D3702, 40 psi (0.28 MPa), 50 ft/min (0.25 m/s)) · bearing grade: 0.18-0.20 (ASTM D3702 (Ensinger USA)) |
| PV limit (pressure × velocity) | CF30: 0.876 MPa·m/s (MCAM QTM 55007, dry against steel, safety factor 4:1 already applied; original 25,000 psi·ft/min); 13.5 MPa·m/s (ASTM D3702 (Ensinger USA), no safety factor stated; original 385,000 psi·ft/min) · bearing grade: 0.701 MPa·m/s (MCAM QTM 55007, dry against steel, safety factor 4:1 already applied; original 20,000 psi·ft/min); 17.5 MPa·m/s (ASTM D3702 (Ensinger USA), no safety factor stated; original "500000" with no explicit unit, assumed psi·ft/min) |
PV and friction depend on the test method, the mating surface (steel, stainless, roughness), lubrication and each manufacturer's safety factor: compare values from the same source and confirm by testing in critical applications.
Chemical resistance
| Medium | Resistance |
|---|---|
| Acids | Good; limited in strong acids |
| Bases (alkalis) | Good (hot alkalis can attack the glass fiber) |
| Solvents | Very good |
| Hydrocarbons and oils | Very good |
| Steam and hot water | Very good |
Stock forms and sizes
- Rod (round bar)
- Sheet (plate)
- Tube and bushing
- Raw material: rod (round bar), sheet (plate) and tube, cut to size
- Machined part to drawing or sample, in the same order as the metal parts
- Lot certificate of conformity; FDA/EU 10/2011 declaration when the grade allows
Service temperature, machining and assembly
| Item | Usual practice |
|---|---|
| Service temperature | Continuous service up to 260 °C, short peaks up to 300 °C; minimum -20 °C (unloaded; under load, limited by HDT and creep). |
| Annealing (stress relief) | Stress-relief annealing before precision machining, as specified by the manufacturer. |
| Bonding and welding | Bonding with epoxy after surface preparation; hot plate welding is possible in GF/CF grades. |
| Machining | Fibers are abrasive: carbide or PCD tooling. CF30 and the bearing grade are conductive (dark powdery chips). |
Typical applications
- Guide rings, bushings and dry-running bearings under high load
- Compressor piston rings and wear rings
- Thrust washers and wear plates
- Lightweight structural parts at high temperature
- Replacement for bronze and babbitt in bearings
Alternatives: Bronze-filled PTFE when the load is moderate and cost matters; PAI (Torlon 4301) for even higher PV and temperature; SAE 660 bronze with good lubrication.
Frequently asked questions
Which standards cover Reinforced PEEK?
Rod, sheet and tube: Stock-shape manufacturer's specification. Machined part to drawing: ISO 2768 tolerance or as per drawing.
Up to what temperature can Reinforced PEEK be used?
Continuous service up to 260 °C, short peaks up to 300 °C; minimum -20 °C (unloaded; under load, limited by HDT and creep).
Which materials can replace Reinforced PEEK?
Bronze-filled PTFE when the load is moderate and cost matters; PAI (Torlon 4301) for even higher PV and temperature; SAE 660 bronze with good lubrication.
GF30, CF30 or bearing grade?
GF30 for stiffness and dimensional stability at lower cost; CF30 for maximum stiffness and low wear; bearing grade when the part slides under load and speed without lubrication.
Why does the PV of PEEK vary so much between catalogs?
Each manufacturer measures differently: some apply a safety factor (MCAM uses 4:1), others publish the test limit (ASTM D3702). Compare PV from the same source and confirm by testing when the application is critical.
