PEEK-GF30 vs PEK
Polymer · grade comparison
PEEK-GF30 and PEK are both polymer grades. PEEK-GF30 is the stronger of the two: tensile strength 165 MPa (23.9 ksi) against 110 MPa (16 ksi) for PEK, about 50% more. In exchange, PEK is the more ductile: elongation 25% versus 2.5% for PEEK-GF30. PEK is lighter (1.3 g/cm³ vs 1.51 g/cm³ for PEEK-GF30) and PEEK-GF30 is stiffer (10 GPa vs 4 GPa). On the shop floor, PEK machines more easily (good vs fair) and PEK welds better (good vs fair).
PEEK-GF30Choose it when strength drives the design.
PEKChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PEEK-GF30 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
Shear Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Yield Strength (0.2% offset)
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (24 h)
Same in both: Water Absorption (Saturation) 0.4%
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
Vicat Softening Point (B50)
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Max Service Temperature (continuous) 260°C500 °F
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Surface Resistivity
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Volume Resistivity 1×10¹⁶ Ω·cm · Comparative Tracking Index (CTI) 150 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: UV / Weathering Resistance 40 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Polishability
Mold Shrinkage
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Melt Flow Rate 4 g/10 min
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 0%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Thermal Diffusivity
Same in both: Thermal Shock Resistance Index 0
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-GF30 | PEK |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
PEEK-GF30 vs PEK — frequently asked
Is PEEK-GF30 stronger than PEK?
Yes. PEEK-GF30 has a typical tensile strength of 165 MPa (23.9 ksi) against 110 MPa (16 ksi) for PEK — about 50% more.
Which is cheaper, PEEK-GF30 or PEK?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, PEEK-GF30 or PEK?
PEK. Its machinability rates good (65/100) against fair (45/100) for PEEK-GF30; for welding the order is PEK first (good, 55/100) then PEEK-GF30 (fair, 35/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PEEK-GF30 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.