CAP vs EC
Polymer · grade comparison
CAP and EC are both polymer grades. CAP is the stronger of the two: yield strength 30 MPa (4.35 ksi) against 26 MPa (3.77 ksi) for EC, about 15% more. CAP is the more ductile: elongation 50% versus 24% for EC. EC is lighter (1.12 g/cm³ vs 1.21 g/cm³ for CAP) and CAP is stiffer (1.4 GPa vs 1.3 GPa).
CAPChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
ECChoose it when weight is the constraint, or when the part sees heat.
CAP vs EC: 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)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Flexural Strength
Flexural Modulus
Shear Strength
Izod Impact, Notched
Hardness, Rockwell R
Shear Modulus
Bulk Modulus
Compressive Modulus
Fracture Toughness (K_IC)
Tear Strength
Same in both: Hardness, Shore D 78 Shore D
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Light Transmission
Same in both: Refractive Index 1.47
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)
Min Service Temperature
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Max Service Temperature (short-term)
Same in both: Limiting Oxygen Index 19%
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Volume Resistivity
Surface Resistivity
Same in both: Comparative Tracking Index (CTI) 600 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
Melt Flow Rate
Processing Melt Temperature (typ.)
Same in both: Mold Temperature (typ.) 55°C131 °F
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Same in both: Embodied Energy (primary production) 100 MJ/kg42,992 BTU/lb · Typical Recycled Content 0%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Modulus of Resilience
Same in both: Specific Stiffness (E / density) 1.2 MN·m/kg · 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 | CAP | EC |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$ Premium | $$$ Premium |
| Min. machined wall | — | — |
| Best machined surface | — | — |
CAP vs EC — frequently asked
Is CAP stronger than EC?
Yes. CAP has a typical yield strength of 30 MPa (4.35 ksi) against 26 MPa (3.77 ksi) for EC — about 15% more. Tensile strength is 32 MPa (4.64 ksi) vs 34 MPa (4.93 ksi).
Which is cheaper, CAP or EC?
Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.
When should I choose CAP over EC?
Pick CAP when strength drives the design, or when the part is bent, formed or impact-loaded. Pick EC when weight is the constraint, or when the part sees heat.
Ready to make it?
Upload a CAD file and FabDigit prices the part in CAP and EC 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.