Graphite vs Silicon Carbide
Ceramic · grade comparison
Graphite and Silicon Carbide are both ceramic grades. Silicon Carbide is the stronger of the two: tensile strength 250 MPa (36.3 ksi) against 30 MPa (4.35 ksi) for Graphite, about 8.3 times as much. Graphite is lighter (1.78 g/cm³ vs 3.15 g/cm³ for Silicon Carbide) and Silicon Carbide is stiffer (410 GPa vs 11 GPa). On the shop floor, Graphite machines more easily (excellent vs not recommended).
GraphiteChoose it when weight is the constraint, or when the part is machined in volume.
Silicon CarbideChoose it when strength drives the design, or when the part sees heat.
Graphite vs Silicon Carbide: 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.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Compressive Strength
Flexural Strength
Shear Strength
Fracture Toughness (K_IC)
Hardness, Mohs
Hardness, Vickers
Hardness, Knoop
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Porosity
Refractive Index
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Same in both: 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
Sintering / Firing Temperature
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Thermal Diffusivity
Thermal Shock Resistance Index
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 | Graphite | Silicon Carbide |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Graphite vs Silicon Carbide — frequently asked
Is Silicon Carbide stronger than Graphite?
Yes. Silicon Carbide has a typical tensile strength of 250 MPa (36.3 ksi) against 30 MPa (4.35 ksi) for Graphite — about 8.3 times as much.
Which is cheaper, Graphite or Silicon Carbide?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, Graphite or Silicon Carbide?
Graphite. Its machinability rates excellent (92/100) against not recommended (3/100) for Silicon Carbide.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Graphite and Silicon Carbide 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.