PEEK-Medical-Grade CF-CONT vs PEEK-Medical-Grade ST
Polymer · PEEK-Medical-Grade grade comparison
PEEK-Medical-Grade CF-CONT and PEEK-Medical-Grade ST are two grades of the same polymer grade, PEEK-Medical-Grade: CF-CONT (continuous / long carbon fibre reinforced) versus ST (solution annealed). The chemistry is identical, so every difference below comes from the condition. PEEK-Medical-Grade CF-CONT is the stronger of the two: yield strength 880 MPa (128 ksi) against 98 MPa (14.2 ksi) for PEEK-Medical-Grade ST, about 9.0 times as much; tensile strength follows at 900 MPa (131 ksi) vs 100 MPa (14.5 ksi). In exchange, PEEK-Medical-Grade ST is the more ductile: elongation 30% versus 1.4% for PEEK-Medical-Grade CF-CONT, and PEEK-Medical-Grade CF-CONT is harder (90 Shore D vs 85 Shore D). PEEK-Medical-Grade ST is lighter (1.3 g/cm³ vs 1.55 g/cm³ for PEEK-Medical-Grade CF-CONT) and PEEK-Medical-Grade CF-CONT is stiffer (100 GPa vs 3.8 GPa). On the shop floor, PEEK-Medical-Grade ST machines more easily (very good vs fair) and PEEK-Medical-Grade ST welds better (good vs poor).
PEEK-Medical-Grade CF-CONTChoose it when strength drives the design.
PEEK-Medical-Grade STChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.
PEEK-Medical-Grade CF-CONT vs PEEK-Medical-Grade ST: 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.
PEEK-Medical-Grade CF-CONTPEEK-Medical-Grade ST
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Same in both: Shear Modulus 1.4 GPa0.2 Msi · Bulk Modulus 4 GPa0.62 Msi · Poisson's Ratio 0.4 · Compressive Modulus 3.6 GPa0.52 Msi · Hardness, Rockwell R 126 HRR
Physical
Density and transition temperatures.
Density
Same in both: Melting Temperature (Tm) 343°C649 °F · Glass Transition (Tg) 143°C289 °F · Water Absorption (24 h) 0.14% · Water Absorption (Saturation) 0.45%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Same in both: Specific Heat Capacity 1,340 J/kg·K0.32 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 47 µm/m·K26.1 µin/in·°F · Max Service Temperature (continuous) 250°C482 °F · Min Service Temperature -60°C-76 °F · Max Service Temperature (short-term) 300°C572 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Same in both: Dielectric Strength 22 kV/mm559 V/mil · Dielectric Constant (1 MHz) 3.2 · Dissipation Factor (1 MHz) 0.003 · Volume Resistivity 1×10¹⁶ Ω·cm · Surface Resistivity 1×10¹⁵ Ω · Comparative Tracking Index (CTI) 150 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: UV / Weathering Resistance 35 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Same in both: Polishability 80 / 100 · Mold Shrinkage 1.2% · Melt Flow Rate 3.5 g/10 min · Processing Melt Temperature (typ.) 380°C716 °F · Mold Temperature (typ.) 190°C374 °F
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 290 MJ/kg124,678 BTU/lb · Embodied Carbon (primary production) 13 kg CO₂/kg · Embodied Water 600 L/kg71.9 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-Medical-Grade CF-CONT vs PEEK-Medical-Grade ST — frequently asked
Is PEEK-Medical-Grade CF-CONT stronger than PEEK-Medical-Grade ST?
Yes. PEEK-Medical-Grade CF-CONT has a typical yield strength of 880 MPa (128 ksi) against 98 MPa (14.2 ksi) for PEEK-Medical-Grade ST — about 9.0 times as much. Tensile strength is 900 MPa (131 ksi) vs 100 MPa (14.5 ksi).
Which grade does FabDigit quote by default, CF-CONT or ST?
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-Medical-Grade CF-CONT or PEEK-Medical-Grade ST?
PEEK-Medical-Grade ST. Its machinability rates very good (70/100) against fair (35/100) for PEEK-Medical-Grade CF-CONT; for welding the order is PEEK-Medical-Grade ST first (good, 60/100) then PEEK-Medical-Grade CF-CONT (poor, 15/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PEEK-Medical-Grade CF-CONT and PEEK-Medical-Grade ST 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.