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CAP vs CN

Polymer · grade comparison

CAP and CN are both polymer grades. CN is the stronger of the two: yield strength 42 MPa (6.09 ksi) against 30 MPa (4.35 ksi) for CAP, about 40% more; tensile strength follows at 52 MPa (7.54 ksi) vs 32 MPa (4.64 ksi). In exchange, CAP is the more ductile: elongation 50% versus 35% for CN. CAP is lighter (1.21 g/cm³ vs 1.38 g/cm³ for CN) and CN is stiffer (1.8 GPa vs 1.4 GPa). On the shop floor, CN welds better (very good vs good).

CAPChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

CNChoose it when strength drives the design, or when it will be welded.

CAP vs CN: properties

CAPCN

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

1.4 GPa0.2 Msi
1.8 GPa0.26 Msi

Poisson's Ratio

0.39
0.4

Tensile Strength (Ultimate)

32 MPa4.6 ksi
52 MPa7.5 ksi

Yield Strength (0.2% offset)

30 MPa4.4 ksi
42 MPa6.1 ksi

Elongation at Break

50%
35%

Compressive Strength

45 MPa6.5 ksi
62 MPa9 ksi

Flexural Strength

45 MPa6.5 ksi
68 MPa9.9 ksi

Flexural Modulus

1.3 GPa0.19 Msi
1.7 GPa0.25 Msi

Shear Strength

26 MPa3.8 ksi
40 MPa5.8 ksi

Izod Impact, Notched

160 J/m3 ft·lbf/in
320 J/m6 ft·lbf/in

Hardness, Shore D

78 Shore D
80 Shore D

Hardness, Rockwell R

95 HRR
105 HRR

Physical

Density and transition temperatures.

Density

1.21 g/cm³0.04 lb/in³
1.38 g/cm³0.05 lb/in³

Melting Temperature (Tm)

190°C374 °F
—

Glass Transition (Tg)

142°C288 °F
55°C131 °F

Water Absorption (Saturation)

3%
4.5%

Refractive Index

1.47
1.5

Light Transmission

89%
88%

Same in both: Water Absorption (24 h) 1.8%

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

0.21 W/m·K0.12 BTU/hr·ft·°F
0.22 W/m·K0.13 BTU/hr·ft·°F

Specific Heat Capacity

1,600 J/kg·K0.38 BTU/lb·°F
1,500 J/kg·K0.36 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

130 µm/m·K72.2 µin/in·°F
110 µm/m·K61.1 µin/in·°F

Max Service Temperature (continuous)

60°C140 °F
55°C131 °F

Min Service Temperature

-40°C-40 °F
-30°C-22 °F

Heat Deflection Temp. @ 0.45 MPa

75°C167 °F
68°C154 °F

Heat Deflection Temp. @ 1.8 MPa

55°C131 °F
52°C126 °F

Vicat Softening Point (B50)

105°C221 °F
75°C167 °F

Limiting Oxygen Index

19%
—

Max Service Temperature (short-term)

90°C194 °F
85°C185 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹² Ω·m3.94×10¹⁹ µΩ·in
1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in

Dielectric Strength

17 kV/mm432 V/mil
16 kV/mm406 V/mil

Dielectric Constant (1 MHz)

3.4
6

Dissipation Factor (1 MHz)

0.02
0.09

Volume Resistivity

1×10¹⁴ Ω·cm
1×10¹³ Ω·cm

Surface Resistivity

1×10¹³ Ω
—

Comparative Tracking Index (CTI)

600 V
—

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

55 / 100
45 / 100

UV / Weathering Resistance

55 / 100
12 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

78 / 100
85 / 100

Weldability

60 / 100
70 / 100

Mold Shrinkage

0.45%
—

Melt Flow Rate

8 g/10 min
—

Processing Melt Temperature (typ.)

215°C419 °F
—

Mold Temperature (typ.)

55°C131 °F
—

Same in both: Formability (cold) 80 / 100 · Polishability 92 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

100 MJ/kg42,992 BTU/lb
95 MJ/kg40,843 BTU/lb

Embodied Water

350 L/kg41.9 gal/lb
250 L/kg30 gal/lb

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)

26 kN·m/kg
38 kN·m/kg

Specific Stiffness (E / density)

1.2 MN·m/kg
1.3 MN·m/kg

Modulus of Resilience

321 kJ/m³
490 kJ/m³

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.

0.1110100123Density (g/cm³)Yield strength (MPa) — log scaleCNCAP

Manufacturing and finishing

CapabilityCAPCN
Default condition——
Relative cost$$$ Premium$$$ Premium
Min. machined wall——
Best machined surface——

CAP vs CN — frequently asked

Is CN stronger than CAP?

Yes. CN has a typical yield strength of 42 MPa (6.09 ksi) against 30 MPa (4.35 ksi) for CAP — about 40% more. Tensile strength is 52 MPa (7.54 ksi) vs 32 MPa (4.64 ksi).

Which is cheaper, CAP or CN?

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.

Which is easier to machine, CAP or CN?

CN. Its machinability rates excellent (85/100) against very good (78/100) for CAP; for welding the order is CN first (very good, 70/100) then CAP (good, 60/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in CAP and CN 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.