RBSiC/SiSiC vs WC-Co
Ceramic · grade comparison
RBSiC/SiSiC and WC-Co are both ceramic grades. WC-Co is the stronger of the two: tensile strength 1,500 MPa (218 ksi) against 200 MPa (29 ksi) for RBSiC/SiSiC, about 7.5 times as much. RBSiC/SiSiC is harder — 2,300 HV against 1,600 HV for WC-Co — which matters for wear surfaces and threads. RBSiC/SiSiC is lighter (3.05 g/cm³ vs 14.9 g/cm³ for WC-Co) and WC-Co is stiffer (630 GPa vs 390 GPa).
RBSiC/SiSiCChoose it when surface hardness matters, or when weight is the constraint.
WC-CoChoose it when strength drives the design.
RBSiC/SiSiC vs WC-Co: 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, Vickers
Hardness, Knoop
Hardness, Mohs
Same in both: Elongation at Break 0%
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Porosity
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 | RBSiC/SiSiC | WC-Co |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
RBSiC/SiSiC vs WC-Co — frequently asked
Is WC-Co stronger than RBSiC/SiSiC?
Yes. WC-Co has a typical tensile strength of 1,500 MPa (218 ksi) against 200 MPa (29 ksi) for RBSiC/SiSiC — about 7.5 times as much.
Which is cheaper, RBSiC/SiSiC or WC-Co?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
When should I choose RBSiC/SiSiC over WC-Co?
Pick RBSiC/SiSiC when surface hardness matters, or when weight is the constraint. Pick WC-Co when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in RBSiC/SiSiC and WC-Co 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.