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C/C Composite vs RP Graphite Electrode

Ceramic · grade comparison

C/C Composite and RP Graphite Electrode are both ceramic grades. C/C Composite is the stronger of the two: tensile strength 200 MPa (29 ksi) against 7 MPa (1.02 ksi) for RP Graphite Electrode, about 29 times as much. C/C Composite is the more ductile: elongation 0.4% versus 0.25% for RP Graphite Electrode. RP Graphite Electrode is lighter (1.56 g/cm³ vs 1.7 g/cm³ for C/C Composite) and C/C Composite is stiffer (60 GPa vs 9 GPa). On the shop floor, RP Graphite Electrode machines more easily (excellent vs fair) and RP Graphite Electrode sits in a lower cost tier (standard, $$) than C/C Composite (high, $$$$).

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

RP Graphite ElectrodeChoose it when weight is the constraint, or when the part is machined in volume.

C/C Composite vs RP Graphite Electrode: properties

C/C CompositeRP Graphite Electrode

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

60 GPa8.7 Msi
9 GPa1.3 Msi

Shear Modulus

5 GPa0.73 Msi
3.8 GPa0.55 Msi

Tensile Strength (Ultimate)

200 MPa29 ksi
7 MPa1 ksi

Elongation at Break

0.4%
0.25%

Compressive Strength

160 MPa23.2 ksi
22 MPa3.2 ksi

Flexural Strength

220 MPa31.9 ksi
11 MPa1.5 ksi

Shear Strength

15 MPa2.2 ksi
6 MPa0.87 ksi

Fracture Toughness (K_IC)

5 MPa·√m4.6 ksi·√in
1 MPa·√m0.91 ksi·√in

Hardness, Vickers

—
32 HV

Hardness, Mohs

—
1.5

Same in both: Poisson's Ratio 0.15

Physical

Density and transition temperatures.

Density

1.7 g/cm³0.06 lb/in³
1.56 g/cm³0.06 lb/in³

Porosity

10%
25%

Same in both: Melting Point (Solidus) 3,650°C6,602 °F

Thermal

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

Thermal Conductivity

40 W/m·K23.1 BTU/hr·ft·°F
140 W/m·K80.9 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

1 µm/m·K0.56 µin/in·°F
2.2 µm/m·K1.2 µin/in·°F

Max Service Temperature (continuous)

2,200°C3,992 °F
450°C842 °F

Same in both: Specific Heat Capacity 710 J/kg·K0.17 BTU/lb·°F · Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

2×10⁻⁵ Ω·m787 µΩ·in
8×10⁻⁶ Ω·m315 µΩ·in

Volume Resistivity

0 Ω·cm
8×10⁻⁴ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

70 / 100
65 / 100

Manufacturability

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

Machinability

35 / 100
90 / 100

Polishability

20 / 100
25 / 100

Sintering / Firing Temperature

2,200°C3,992 °F
2,900°C5,252 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

750 MJ/kg322,442 BTU/lb
65 MJ/kg27,945 BTU/lb

Embodied Carbon (primary production)

55 kg CO₂/kg
6 kg CO₂/kg

Embodied Water

900 L/kg108 gal/lb
25 L/kg3 gal/lb

Typical Recycled Content

0%
5%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

118 kN·m/kg
4 kN·m/kg

Specific Stiffness (E / density)

35.3 MN·m/kg
5.8 MN·m/kg

Thermal Diffusivity

33.1 mm²/s
126.4 mm²/s

Thermal Shock Resistance Index

133
49

Strength versus weight

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

501002005001,000234567Density (g/cm³)Yield strength (MPa) — log scale

Manufacturing and finishing

CapabilityC/C CompositeRP Graphite Electrode
Default condition——
Relative cost$$$$ High$$ Standard
Min. machined wall——
Best machined surface——

C/C Composite vs RP Graphite Electrode — frequently asked

Is C/C Composite stronger than RP Graphite Electrode?

Yes. C/C Composite has a typical tensile strength of 200 MPa (29 ksi) against 7 MPa (1.02 ksi) for RP Graphite Electrode — about 29 times as much.

Which is cheaper, C/C Composite or RP Graphite Electrode?

RP Graphite Electrode is the lower-cost material: it sits in the standard tier ($$) while C/C Composite is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, C/C Composite or RP Graphite Electrode?

RP Graphite Electrode. Its machinability rates excellent (90/100) against fair (35/100) for C/C Composite.

Ready to make it?

Upload a CAD file and FabDigit prices the part in C/C Composite and RP Graphite Electrode 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.