PEEK Annealed vs PEEK GF20
Polymer · PEEK grade comparison
PEEK Annealed and PEEK GF20 are two grades of the same polymer grade, PEEK: Annealed versus GF20 (20% Glass Fiber). The chemistry is identical, so every difference below comes from the condition. PEEK GF20 is the stronger of the two: tensile strength 140 MPa (20.3 ksi) against 95 MPa (13.8 ksi) for PEEK Annealed, about 47% more. In exchange, PEEK Annealed is the more ductile: elongation 12% versus 3% for PEEK GF20. PEEK Annealed is lighter (1.3 g/cm³ vs 1.44 g/cm³ for PEEK GF20) and PEEK GF20 is stiffer (7.5 GPa vs 3.9 GPa). On the shop floor, PEEK Annealed machines more easily (very good vs good) and PEEK Annealed welds better (fair vs poor).
PEEK AnnealedChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PEEK GF20Choose it when strength drives the design.
PEEK Annealed vs PEEK GF20: 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
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Rockwell M
Same in both: Shear Modulus 1.3 GPa0.19 Msi · Bulk Modulus 6 GPa0.87 Msi · Yield Strength (0.2% offset) 100 MPa14.5 ksi · Hardness, Shore D 87 Shore D · Hardness, Rockwell R 126 HRR
Physical
Density and transition temperatures.
Density
Water Absorption (24 h)
Water Absorption (Saturation)
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
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Max Service Temperature (short-term)
Same in both: Min Service Temperature -60°C-76 °F · Limiting Oxygen Index 35%
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume Resistivity
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 150 V
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
Mold Temperature (typ.)
Same in both: Melt Flow Rate 3 g/10 min · Processing Melt Temperature (typ.) 380°C716 °F
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Same in both: Embodied Carbon (primary production) 15 kg CO₂/kg · Embodied Water 450 L/kg53.9 gal/lb · Typical Recycled Content 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.
PEEK Annealed vs PEEK GF20 — frequently asked
Is PEEK GF20 stronger than PEEK Annealed?
Yes. PEEK GF20 has a typical tensile strength of 140 MPa (20.3 ksi) against 95 MPa (13.8 ksi) for PEEK Annealed — about 47% more.
Which grade does FabDigit quote by default, Annealed or GF20?
Specify the condition in the material field or the drawing note; FabDigit prices the quote for the state you call out.
Which is easier to machine, PEEK Annealed or PEEK GF20?
PEEK Annealed. Its machinability rates very good (70/100) against good (55/100) for PEEK GF20; for welding the order is PEEK Annealed first (fair, 45/100) then PEEK GF20 (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PEEK Annealed and PEEK GF20 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.