PEEK-CF30 vs PEK
Polymer · grade comparison
PEEK-CF30 and PEK are both polymer grades. PEEK-CF30 is the stronger of the two: tensile strength 235 MPa (34.1 ksi) against 110 MPa (16 ksi) for PEK, about 114% more. In exchange, PEK is the more ductile: elongation 25% versus 1.7% for PEEK-CF30. PEK is lighter (1.3 g/cm³ vs 1.41 g/cm³ for PEEK-CF30) and PEEK-CF30 is stiffer (24 GPa vs 4 GPa). On the shop floor, PEK machines more easily (65 vs 55 out of 100) and PEK welds better (good vs fair).
PEEK-CF30Choose it when strength drives the design.
PEKChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PEEK-CF30 vs PEK: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Shear Modulus
Yield Strength (0.2% offset)
Fracture Toughness (K_IC)
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Min Service Temperature
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Limiting Oxygen Index
Max Service Temperature (short-term)
Vicat Softening Point (B50)
Same in both: Max Service Temperature (continuous) 260°C500 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Volume Resistivity
Surface Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Comparative Tracking Index (CTI)
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
UV / Weathering Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Polishability
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Same in both: Embodied Energy (primary production) 320 MJ/kg137,575 BTU/lb · Typical Recycled Content 0%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Thermal Diffusivity
Thermal Shock Resistance Index
Strength versus weight
Yield strength against density for every polymer grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | PEEK-CF30 | PEK |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
PEEK-CF30 vs PEK — frequently asked
Is PEEK-CF30 stronger than PEK?
Yes. PEEK-CF30 has a typical tensile strength of 235 MPa (34.1 ksi) against 110 MPa (16 ksi) for PEK — about 114% more.
Which is cheaper, PEEK-CF30 or PEK?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, PEEK-CF30 or PEK?
PEK, by a small margin. Both rate good for machinability — 65/100 against 55/100 for PEEK-CF30; for welding the order is PEK first (good, 55/100) then PEEK-CF30 (fair, 35/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PEEK-CF30 and PEK side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.