HP Graphite Electrode vs RP Graphite Electrode
Ceramic · grade comparison
HP Graphite Electrode and RP Graphite Electrode are both ceramic grades. HP Graphite Electrode is the stronger of the two: tensile strength 8 MPa (1.09 ksi) against 7 MPa (1.02 ksi) for RP Graphite Electrode, about 7% more. RP Graphite Electrode is lighter (1.56 g/cm³ vs 1.7 g/cm³ for HP Graphite Electrode) and HP Graphite Electrode is stiffer (12 GPa vs 9 GPa).
HP Graphite ElectrodeChoose it when strength drives the design, or when the part sees heat.
RP Graphite ElectrodeChoose it when weight is the constraint.
HP Graphite Electrode vs RP Graphite Electrode: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all ceramic grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all ceramic grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
HP Graphite ElectrodeRP Graphite Electrode
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Compressive Strength
Flexural Strength
Shear Modulus
Elongation at Break
Hardness, Vickers
Same in both: Shear Strength 6 MPa0.87 ksi · Fracture Toughness (K_IC) 1 MPa·√m0.91 ksi·√in · Hardness, Mohs 1.5
Physical
Density and transition temperatures.
Density
Porosity
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
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
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
Volume Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Polishability
Same in both: Sintering / Firing Temperature 2,900°C5,252 °F
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 5%
Common Calculations
Ratios derived from the values above.
Specific Stiffness (E / density)
Thermal Diffusivity
Thermal Shock Resistance Index
Same in both: Specific Strength (UTS / density) 4 kN·m/kg
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.
Manufacturing and finishing
| Capability | HP Graphite Electrode | RP Graphite Electrode |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
HP Graphite Electrode vs RP Graphite Electrode — frequently asked
Is HP Graphite Electrode stronger than RP Graphite Electrode?
Yes. HP Graphite Electrode has a typical tensile strength of 8 MPa (1.09 ksi) against 7 MPa (1.02 ksi) for RP Graphite Electrode — about 7% more.
Which is cheaper, HP Graphite Electrode or RP Graphite Electrode?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
When should I choose HP Graphite Electrode over RP Graphite Electrode?
Pick HP Graphite Electrode when strength drives the design, or when the part sees heat. Pick RP Graphite Electrode when weight is the constraint.
Ready to make it?
Upload a CAD file and FabDigit prices the part in HP Graphite Electrode 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.