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Cyanate Ester vs DAP

Polymer · grade comparison

Cyanate Ester and DAP are both polymer grades. Cyanate Ester is the stronger of the two: tensile strength 80 MPa (11.6 ksi) against 55 MPa (7.98 ksi) for DAP, about 45% more. Cyanate Ester is the more ductile: elongation 2.6% versus 0.6% for DAP. Cyanate Ester is lighter (1.21 g/cm³ vs 1.8 g/cm³ for DAP) and DAP is stiffer (10.5 GPa vs 3.1 GPa). On the shop floor, Cyanate Ester machines more easily (good vs fair).

Cyanate EsterChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

Cyanate Ester vs DAP: properties

Cyanate EsterDAP

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

3.1 GPa0.45 Msi
10.5 GPa1.5 Msi

Shear Modulus

1.2 GPa0.17 Msi
—

Bulk Modulus

4 GPa0.52 Msi
—

Poisson's Ratio

0.35
0.32

Tensile Strength (Ultimate)

80 MPa11.6 ksi
55 MPa8 ksi

Elongation at Break

2.6%
0.6%

Compressive Strength

175 MPa25.4 ksi
200 MPa29 ksi

Compressive Modulus

3.3 GPa0.48 Msi
—

Flexural Strength

140 MPa20.3 ksi
105 MPa15.2 ksi

Flexural Modulus

3.2 GPa0.46 Msi
11 GPa1.6 Msi

Shear Strength

55 MPa8 ksi
—

Fracture Toughness (K_IC)

0.6 MPa·√m0.55 ksi·√in
—

Izod Impact, Notched

20 J/m0.37 ft·lbf/in
40 J/m0.75 ft·lbf/in

Hardness, Shore D

89 Shore D
—

Same in both: Hardness, Rockwell M 110 HRM

Physical

Density and transition temperatures.

Density

1.21 g/cm³0.04 lb/in³
1.8 g/cm³0.07 lb/in³

Glass Transition (Tg)

270°C518 °F
160°C320 °F

Water Absorption (24 h)

0.5%
0.2%

Water Absorption (Saturation)

2.3%
0.6%

Refractive Index

1.57
—

Thermal

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

Thermal Conductivity

0.24 W/m·K0.14 BTU/hr·ft·°F
0.5 W/m·K0.29 BTU/hr·ft·°F

Specific Heat Capacity

1,150 J/kg·K0.27 BTU/lb·°F
1,050 J/kg·K0.25 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

63 µm/m·K35 µin/in·°F
25 µm/m·K13.9 µin/in·°F

Max Service Temperature (continuous)

200°C392 °F
180°C356 °F

Min Service Temperature

-200°C-328 °F
-60°C-76 °F

Heat Deflection Temp. @ 0.45 MPa

265°C509 °F
285°C545 °F

Heat Deflection Temp. @ 1.8 MPa

250°C482 °F
265°C509 °F

Limiting Oxygen Index

33%
32%

Max Service Temperature (short-term)

300°C572 °F
230°C446 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹⁴ Ω·m3.94×10²¹ µΩ·in
1×10¹³ Ω·m3.94×10²⁰ µΩ·in

Dielectric Strength

22 kV/mm559 V/mil
16 kV/mm406 V/mil

Dielectric Constant (1 MHz)

2.9
4.3

Dissipation Factor (1 MHz)

0.004
0.011

Volume Resistivity

1×10¹⁶ Ω·cm
1×10¹⁵ Ω·cm

Surface Resistivity

1×10¹⁵ Ω
1×10¹⁴ Ω

Same in both: Comparative Tracking Index (CTI) 200 V

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

82 / 100
80 / 100

UV / Weathering Resistance

30 / 100
55 / 100

Manufacturability

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

Machinability

55 / 100
40 / 100

Formability (cold)

5 / 100
0 / 100

Polishability

65 / 100
45 / 100

Mold Shrinkage

0.6%
0.4%

Processing Melt Temperature (typ.)

90°C194 °F
—

Mold Temperature (typ.)

180°C356 °F
160°C320 °F

Same in both: Weldability 0 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

185 MJ/kg79,536 BTU/lb
105 MJ/kg45,142 BTU/lb

Embodied Carbon (primary production)

9.5 kg CO₂/kg
5.5 kg CO₂/kg

Embodied Water

300 L/kg35.9 gal/lb
—

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

66 kN·m/kg
31 kN·m/kg

Specific Stiffness (E / density)

2.6 MN·m/kg
5.8 MN·m/kg

Thermal Diffusivity

0.2 mm²/s
0.3 mm²/s

Same in both: 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 scale

Manufacturing and finishing

CapabilityCyanate EsterDAP
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Cyanate Ester vs DAP — frequently asked

Is Cyanate Ester stronger than DAP?

Yes. Cyanate Ester has a typical tensile strength of 80 MPa (11.6 ksi) against 55 MPa (7.98 ksi) for DAP — about 45% more.

Which is cheaper, Cyanate Ester or DAP?

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, Cyanate Ester or DAP?

Cyanate Ester. Its machinability rates good (55/100) against fair (40/100) for DAP.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Cyanate Ester and DAP 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.