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PEEK CF30 vs PEEK GF30

Polymer · grade comparison

PEEK-CF30 and PEEK-GF30 are both polymer grades. PEEK-CF30 is the stronger of the two: tensile strength 235 MPa (34.1 ksi) against 165 MPa (23.9 ksi) for PEEK-GF30, about 42% more. In exchange, PEEK-GF30 is the more ductile: elongation 2.5% versus 1.7% for PEEK-CF30. PEEK-CF30 is lighter (1.41 g/cm³ vs 1.51 g/cm³ for PEEK-GF30) and PEEK-CF30 is stiffer (24 GPa vs 10 GPa). On the shop floor, PEEK-CF30 machines more easily (good vs fair).

PEEK-CF30Choose it when strength drives the design, or when weight is the constraint.

PEEK-GF30Choose it when the part is bent, formed or impact-loaded.

PEEK-CF30 vs PEEK-GF30: properties

PEEK-CF30PEEK-GF30

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

24 GPa3.5 Msi
10 GPa1.5 Msi

Tensile Strength (Ultimate)

235 MPa34.1 ksi
165 MPa23.9 ksi

Elongation at Break

1.7%
2.5%

Compressive Strength

250 MPa36.3 ksi
210 MPa30.5 ksi

Compressive Modulus

16 GPa2.3 Msi
8 GPa1.2 Msi

Flexural Strength

340 MPa49.3 ksi
235 MPa34.1 ksi

Flexural Modulus

20 GPa2.9 Msi
9.7 GPa1.4 Msi

Shear Strength

95 MPa13.8 ksi
100 MPa14.5 ksi

Izod Impact, Notched

60 J/m1.1 ft·lbf/in
95 J/m1.8 ft·lbf/in

Hardness, Rockwell M

105 HRM
102 HRM

Shear Modulus

—
3.6 GPa0.52 Msi

Fracture Toughness (K_IC)

—
5 MPa·√m4.6 ksi·√in

Same in both: Poisson's Ratio 0.38 · Hardness, Shore D 88 Shore D

Physical

Density and transition temperatures.

Density

1.41 g/cm³0.05 lb/in³
1.51 g/cm³0.05 lb/in³

Water Absorption (24 h)

0.08%
0.11%

Water Absorption (Saturation)

0.3%
0.4%

Same in both: Melting Temperature (Tm) 343°C649 °F · Glass Transition (Tg) 143°C289 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

0.9 W/m·K0.52 BTU/hr·ft·°F
0.43 W/m·K0.25 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

12 µm/m·K6.7 µin/in·°F
20 µm/m·K11.1 µin/in·°F

Limiting Oxygen Index

35%
38%

Vicat Softening Point (B50)

—
330°C626 °F

Same in both: Specific Heat Capacity 1,050 J/kg·K0.25 BTU/lb·°F · Max Service Temperature (continuous) 260°C500 °F · Min Service Temperature -60°C-76 °F · Heat Deflection Temp. @ 0.45 MPa 340°C644 °F · Heat Deflection Temp. @ 1.8 MPa 315°C599 °F · Max Service Temperature (short-term) 310°C590 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

100 Ω·m3.94×10⁹ µΩ·in
1×10¹⁴ Ω·m3.94×10²¹ µΩ·in

Volume Resistivity

10,000 Ω·cm
1×10¹⁶ Ω·cm

Surface Resistivity

100,000 Ω
1×10¹⁵ Ω

Dielectric Strength

—
19 kV/mm483 V/mil

Dielectric Constant (1 MHz)

—
3.8

Dissipation Factor (1 MHz)

—
0.005

Comparative Tracking Index (CTI)

—
150 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

92 / 100
93 / 100

UV / Weathering Resistance

70 / 100
40 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

55 / 100
45 / 100

Polishability

40 / 100
30 / 100

Melt Flow Rate

3 g/10 min
4 g/10 min

Processing Melt Temperature (typ.)

385°C725 °F
380°C716 °F

Same in both: Weldability 35 / 100 · Formability (cold) 10 / 100 · Mold Shrinkage 0.3% · Mold Temperature (typ.) 190°C374 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

320 MJ/kg137,575 BTU/lb
260 MJ/kg111,780 BTU/lb

Embodied Carbon (primary production)

18 kg CO₂/kg
13 kg CO₂/kg

Embodied Water

450 L/kg53.9 gal/lb
300 L/kg35.9 gal/lb

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

167 kN·m/kg
109 kN·m/kg

Specific Stiffness (E / density)

17 MN·m/kg
6.6 MN·m/kg

Thermal Diffusivity

0.6 mm²/s
0.3 mm²/s

Thermal Shock Resistance Index

1
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.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scale

Manufacturing and finishing

CapabilityPEEK-CF30PEEK-GF30
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

PEEK-CF30 vs PEEK-GF30 — frequently asked

Is PEEK-CF30 stronger than PEEK-GF30?

Yes. PEEK-CF30 has a typical tensile strength of 235 MPa (34.1 ksi) against 165 MPa (23.9 ksi) for PEEK-GF30 — about 42% more.

Which is cheaper, PEEK-CF30 or PEEK-GF30?

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 PEEK-GF30?

PEEK-CF30. Its machinability rates good (55/100) against fair (45/100) for PEEK-GF30.

Ready to make it?

Upload a CAD file and FabDigit prices the part in PEEK-CF30 and PEEK-GF30 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.