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C/C vs C/C-SiC

Composite · grade comparison

C/C and C/C-SiC are both composite grades. C/C is the stronger of the two: tensile strength 120 MPa (17.4 ksi) against 110 MPa (16 ksi) for C/C-SiC, about 9% more. C/C is the more ductile: elongation 0.5% versus 0.3% for C/C-SiC. C/C is lighter (1.75 g/cm³ vs 1.95 g/cm³ for C/C-SiC) and C/C-SiC runs hotter in service (1,350°C vs 450°C continuous). On the shop floor, C/C machines more easily (fair vs not recommended).

C/CChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

C/C-SiCChoose it when the part sees heat.

C/C vs C/C-SiC: properties

C/CC/C-SiC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

6 GPa0.87 Msi
25 GPa3.6 Msi

Poisson's Ratio

0.15
0.18

Tensile Strength (Ultimate)

120 MPa17.4 ksi
110 MPa16 ksi

Elongation at Break

0.5%
0.3%

Compressive Strength

150 MPa21.8 ksi
260 MPa37.7 ksi

Compressive Modulus

45 GPa6.5 Msi
60 GPa8.7 Msi

Flexural Strength

160 MPa23.2 ksi
230 MPa33.4 ksi

Flexural Modulus

55 GPa8 Msi
60 GPa8.7 Msi

Shear Strength

14 MPa2 ksi
28 MPa4.1 ksi

Fracture Toughness (K_IC)

6 MPa·√m5.5 ksi·√in
5 MPa·√m4.6 ksi·√in

Same in both: Elastic (Young's) Modulus 60 GPa8.7 Msi

Physical

Density and transition temperatures.

Density

1.75 g/cm³0.06 lb/in³
1.95 g/cm³0.07 lb/in³

Thermal

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

Thermal Conductivity

40 W/m·K23.1 BTU/hr·ft·°F
20 W/m·K11.6 BTU/hr·ft·°F

Specific Heat Capacity

720 J/kg·K0.17 BTU/lb·°F
900 J/kg·K0.21 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

1 µm/m·K0.56 µin/in·°F
1.5 µm/m·K0.83 µin/in·°F

Max Service Temperature (continuous)

450°C842 °F
1,350°C2,462 °F

Min Service Temperature

-269°C-452 °F
-180°C-292 °F

Max Service Temperature (short-term)

2,500°C4,532 °F
1,700°C3,092 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

2×10⁻⁵ Ω·m787 µΩ·in
5×10⁻⁴ Ω·m19,685 µΩ·in

Volume Resistivity

0 Ω·cm
—

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

80 / 100
75 / 100

UV / Weathering Resistance

100 / 100
98 / 100

Manufacturability

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

Machinability

40 / 100
8 / 100

Polishability

25 / 100
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

1,000 MJ/kg429,923 BTU/lb
900 MJ/kg386,931 BTU/lb

Embodied Water

400 L/kg47.9 gal/lb
—

Same in both: Embodied Carbon (primary production) 60 kg CO₂/kg · Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

69 kN·m/kg
56 kN·m/kg

Specific Stiffness (E / density)

34.3 MN·m/kg
30.8 MN·m/kg

Thermal Diffusivity

31.7 mm²/s
11.4 mm²/s

Thermal Shock Resistance Index

80
24

Strength versus weight

Yield strength against density for every composite grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

1101001,000510Density (g/cm³)Yield strength (MPa) — log scale

Manufacturing and finishing

CapabilityC/CC/C-SiC
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

C/C vs C/C-SiC — frequently asked

Is C/C stronger than C/C-SiC?

Yes. C/C has a typical tensile strength of 120 MPa (17.4 ksi) against 110 MPa (16 ksi) for C/C-SiC — about 9% more.

Which is cheaper, C/C or C/C-SiC?

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, C/C or C/C-SiC?

C/C. Its machinability rates fair (40/100) against not recommended (8/100) for C/C-SiC.

Ready to make it?

Upload a CAD file and FabDigit prices the part in C/C and C/C-SiC 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.