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Flexible Graphite vs RP Graphite Electrode

Ceramic · grade comparison

Flexible Graphite and RP Graphite Electrode are both ceramic grades. RP Graphite Electrode is the stronger of the two: tensile strength 7 MPa (1.02 ksi) against 5 MPa (0.725 ksi) for Flexible Graphite, about 40% more. In exchange, Flexible Graphite is the more ductile: elongation 2% versus 0.25% for RP Graphite Electrode. Flexible Graphite is lighter (1 g/cm³ vs 1.56 g/cm³ for RP Graphite Electrode) and RP Graphite Electrode is stiffer (9 GPa vs 2 GPa). On the shop floor, RP Graphite Electrode sits in a lower cost tier (standard, $$) than Flexible Graphite (premium, $$$).

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

RP Graphite ElectrodeChoose it when strength drives the design, or when cost is the deciding factor.

Flexible Graphite vs RP Graphite Electrode: properties

Flexible GraphiteRP Graphite Electrode

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

2 GPa0.29 Msi
9 GPa1.3 Msi

Tensile Strength (Ultimate)

5 MPa0.73 ksi
7 MPa1 ksi

Elongation at Break

2%
0.25%

Compressive Strength

60 MPa8.7 ksi
22 MPa3.2 ksi

Flexural Strength

4 MPa0.58 ksi
11 MPa1.5 ksi

Shear Strength

2 MPa0.29 ksi
6 MPa0.87 ksi

Hardness, Mohs

1
1.5

Shear Modulus

—
3.8 GPa0.55 Msi

Poisson's Ratio

—
0.15

Fracture Toughness (K_IC)

—
1 MPa·√m0.91 ksi·√in

Hardness, Vickers

—
32 HV

Physical

Density and transition temperatures.

Density

1 g/cm³0.04 lb/in³
1.56 g/cm³0.06 lb/in³

Porosity

55%
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

150 W/m·K86.7 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

Same in both: Specific Heat Capacity 710 J/kg·K0.17 BTU/lb·°F · Max Service Temperature (continuous) 450°C842 °F · Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10⁻⁵ Ω·m394 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

90 / 100
65 / 100

Manufacturability

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

Polishability

—
25 / 100

Sintering / Firing Temperature

—
2,900°C5,252 °F

Same in both: Machinability 90 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

60 MJ/kg25,795 BTU/lb
65 MJ/kg27,945 BTU/lb

Embodied Carbon (primary production)

5 kg CO₂/kg
6 kg CO₂/kg

Embodied Water

200 L/kg24 gal/lb
25 L/kg3 gal/lb

Same in both: Typical Recycled Content 5%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

5 kN·m/kg
4 kN·m/kg

Specific Stiffness (E / density)

2 MN·m/kg
5.8 MN·m/kg

Thermal Diffusivity

211.3 mm²/s
126.4 mm²/s

Thermal Shock Resistance Index

375
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

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

Flexible Graphite vs RP Graphite Electrode — frequently asked

Is RP Graphite Electrode stronger than Flexible Graphite?

Yes. RP Graphite Electrode has a typical tensile strength of 7 MPa (1.02 ksi) against 5 MPa (0.725 ksi) for Flexible Graphite — about 40% more.

Which is cheaper, Flexible Graphite or RP Graphite Electrode?

RP Graphite Electrode is the lower-cost material: it sits in the standard tier ($$) while Flexible Graphite is premium ($$$). 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 Flexible Graphite over RP Graphite Electrode?

Pick Flexible Graphite when the part is bent, formed or impact-loaded, or when weight is the constraint. Pick RP Graphite Electrode when strength drives the design, or when cost is the deciding factor.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Flexible 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.