FabDigitFabDigit

Nuclear Graphite vs RP Graphite Electrode

Ceramic · grade comparison

Nuclear Graphite and RP Graphite Electrode are both ceramic grades. Nuclear Graphite is the stronger of the two: tensile strength 25 MPa (3.63 ksi) against 7 MPa (1.02 ksi) for RP Graphite Electrode, about 3.6 times as much. RP Graphite Electrode is lighter (1.56 g/cm³ vs 1.78 g/cm³ for Nuclear Graphite) and Nuclear Graphite is stiffer (9.8 GPa vs 9 GPa). On the shop floor, RP Graphite Electrode sits in a lower cost tier (standard, $$) than Nuclear Graphite (high, $$$$).

Nuclear GraphiteChoose it when strength drives the design, or when the part sees heat.

RP Graphite ElectrodeChoose it when weight is the constraint, or when cost is the deciding factor.

Nuclear Graphite vs RP Graphite Electrode: properties

Nuclear GraphiteRP Graphite Electrode

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

9.8 GPa1.4 Msi
9 GPa1.3 Msi

Shear Modulus

4.4 GPa0.64 Msi
3.8 GPa0.55 Msi

Bulk Modulus

5 GPa0.67 Msi
—

Poisson's Ratio

0.14
0.15

Tensile Strength (Ultimate)

25 MPa3.6 ksi
7 MPa1 ksi

Compressive Strength

78 MPa11.3 ksi
22 MPa3.2 ksi

Flexural Strength

39 MPa5.7 ksi
11 MPa1.5 ksi

Shear Strength

22 MPa3.2 ksi
6 MPa0.87 ksi

Fracture Toughness (K_IC)

0.9 MPa·√m0.82 ksi·√in
1 MPa·√m0.91 ksi·√in

Elongation at Break

—
0.25%

Hardness, Vickers

—
32 HV

Same in both: Hardness, Mohs 1.5

Physical

Density and transition temperatures.

Density

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

Porosity

20%
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

120 W/m·K69.3 BTU/hr·ft·°F
140 W/m·K80.9 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

4.5 µm/m·K2.5 µin/in·°F
2.2 µm/m·K1.2 µin/in·°F

Max Service Temperature (continuous)

2,500°C4,532 °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

1.1×10⁻⁵ Ω·m433 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

75 / 100
65 / 100

Manufacturability

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

Machinability

93 / 100
90 / 100

Polishability

35 / 100
25 / 100

Same in both: Sintering / Firing Temperature 2,900°C5,252 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

180 MJ/kg77,386 BTU/lb
65 MJ/kg27,945 BTU/lb

Embodied Carbon (primary production)

14 kg CO₂/kg
6 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
25 L/kg3 gal/lb

Typical Recycled Content

0%
5%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

14 kN·m/kg
4 kN·m/kg

Specific Stiffness (E / density)

5.5 MN·m/kg
5.8 MN·m/kg

Thermal Diffusivity

95 mm²/s
126.4 mm²/s

Thermal Shock Resistance Index

68
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

CapabilityNuclear GraphiteRP Graphite Electrode
Default condition——
Relative cost$$$$ High$$ Standard
Min. machined wall——
Best machined surface——

Nuclear Graphite vs RP Graphite Electrode — frequently asked

Is Nuclear Graphite stronger than RP Graphite Electrode?

Yes. Nuclear Graphite has a typical tensile strength of 25 MPa (3.63 ksi) against 7 MPa (1.02 ksi) for RP Graphite Electrode — about 3.6 times as much.

Which is cheaper, Nuclear Graphite or RP Graphite Electrode?

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

When should I choose Nuclear Graphite over RP Graphite Electrode?

Pick Nuclear Graphite when strength drives the design, or when the part sees heat. Pick RP Graphite Electrode when weight is the constraint, or when cost is the deciding factor.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Nuclear Graphite 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.