PEEK-450G vs PEK
Polymer · grade comparison
PEEK-450G and PEK are both polymer grades. PEK is the stronger of the two: tensile strength 110 MPa (16 ksi) against 100 MPa (14.5 ksi) for PEEK-450G, about 10% more. In exchange, PEEK-450G is the more ductile: elongation 45% versus 25% for PEK. PEK is stiffer (4 GPa vs 3.8 GPa).
PEEK-450GChoose it when the part is bent, formed or impact-loaded.
PEKChoose it when strength drives the design.
PEEK-450G 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
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Hardness, Rockwell R
Same in both: Flexural Strength 165 MPa23.9 ksi
Physical
Density and transition temperatures.
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Refractive Index
Same in both: Density 1.3 g/cm³0.05 lb/in³
Thermal
How each material carries heat and how hot it can run.
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
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: Thermal Conductivity 0.25 W/m·K0.14 BTU/hr·ft·°F · Specific Heat Capacity 1,340 J/kg·K0.32 BTU/lb·°F
Electrical
Conductivity and insulation.
Dielectric Constant (1 MHz)
Same in both: Electrical Resistivity 1×10¹⁴ Ω·m3.94×10²¹ µΩ·in · Dielectric Strength 20 kV/mm508 V/mil · Dissipation Factor (1 MHz) 0.003 · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁶ Ω · 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
Formability (cold)
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
Same in both: Weldability 55 / 100 · Polishability 70 / 100
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)
Modulus of Resilience
Same in both: Thermal Diffusivity 0.1 mm²/s · 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-450G | PEK |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
PEEK-450G vs PEK — frequently asked
Is PEK stronger than PEEK-450G?
Yes. PEK has a typical tensile strength of 110 MPa (16 ksi) against 100 MPa (14.5 ksi) for PEEK-450G — about 10% more.
Which is cheaper, PEEK-450G or PEK?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, PEEK-450G or PEK?
PEEK-450G. Its machinability rates very good (70/100) against good (65/100) for PEK.
Ready to make it?
Upload a CAD file and FabDigit prices the part in PEEK-450G 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.