CAB vs CAP
Polymer · grade comparison
CAB and CAP are both polymer grades. CAP is the stronger of the two: yield strength 30 MPa (4.35 ksi) against 28 MPa (4.06 ksi) for CAB, about 7% more. In exchange, CAB is the more ductile: elongation 60% versus 50% for CAP. CAB runs hotter in service (70°C vs 60°C continuous).
CABChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
CAPChoose it when strength drives the design.
CAB vs CAP: 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.
Shear Modulus
Bulk Modulus
Poisson's Ratio
Yield Strength (0.2% offset)
Elongation at Break
Compressive Modulus
Shear Strength
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Same in both: Elastic (Young's) Modulus 1.4 GPa0.2 Msi · Tensile Strength (Ultimate) 32 MPa4.6 ksi · Compressive Strength 45 MPa6.5 ksi · Flexural Strength 45 MPa6.5 ksi · Flexural Modulus 1.3 GPa0.19 Msi · Hardness, Rockwell R 95 HRR
Physical
Density and transition temperatures.
Density
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Refractive Index
Melting Temperature (Tm)
Same in both: Light Transmission 89%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Limiting Oxygen Index
Max Service Temperature (short-term)
Same in both: Specific Heat Capacity 1,600 J/kg·K0.38 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 130 µm/m·K72.2 µin/in·°F · Min Service Temperature -40°C-40 °F · Heat Deflection Temp. @ 0.45 MPa 75°C167 °F
Electrical
Conductivity and insulation.
Dielectric Strength
Dissipation Factor (1 MHz)
Surface Resistivity
Same in both: Electrical Resistivity 1×10¹² Ω·m3.94×10¹⁹ µΩ·in · Dielectric Constant (1 MHz) 3.4 · Volume Resistivity 1×10¹⁴ Ω·cm · 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
Polishability
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Same in both: Weldability 60 / 100 · Formability (cold) 80 / 100 · Mold Temperature (typ.) 55°C131 °F
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Water
Same in both: Embodied Carbon (primary production) 4.5 kg CO₂/kg · 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 | CAB | CAP |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$ Premium | $$$ Premium |
| Min. machined wall | — | — |
| Best machined surface | — | — |
CAB vs CAP — frequently asked
Is CAP stronger than CAB?
Yes. CAP has a typical yield strength of 30 MPa (4.35 ksi) against 28 MPa (4.06 ksi) for CAB — about 7% more. Tensile strength is 32 MPa (4.64 ksi) vs 32 MPa (4.64 ksi).
Which is cheaper, CAB or CAP?
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 CAB over CAP?
Pick CAB when the part is bent, formed or impact-loaded, or when the part sees heat. Pick CAP when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in CAB and CAP 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.