Boron Nitride vs Silicon Nitride
Ceramic · grade comparison
Boron Nitride and Silicon Nitride are both ceramic grades. Silicon Nitride is the stronger of the two: tensile strength 450 MPa (65.3 ksi) against 35 MPa (5.08 ksi) for Boron Nitride, about 13 times as much. Boron Nitride is lighter (2 g/cm³ vs 3.22 g/cm³ for Silicon Nitride) and Silicon Nitride is stiffer (310 GPa vs 45 GPa). On the shop floor, Boron Nitride machines more easily (excellent vs not recommended).
Boron NitrideChoose it when weight is the constraint, or when the part is machined in volume.
Silicon NitrideChoose it when strength drives the design, or when the part sees heat.
Boron Nitride vs Silicon Nitride: 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
Fracture Toughness (K_IC)
Hardness, Mohs
Elongation at Break
Hardness, Vickers
Hardness, Knoop
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Refractive Index
Porosity
Light Transmission
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)
Min Service Temperature
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
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
Same in both: Typical Recycled Content 0%
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 | Boron Nitride | Silicon Nitride |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Boron Nitride vs Silicon Nitride — frequently asked
Is Silicon Nitride stronger than Boron Nitride?
Yes. Silicon Nitride has a typical tensile strength of 450 MPa (65.3 ksi) against 35 MPa (5.08 ksi) for Boron Nitride — about 13 times as much.
Which is cheaper, Boron Nitride or Silicon Nitride?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, Boron Nitride or Silicon Nitride?
Boron Nitride. Its machinability rates excellent (85/100) against not recommended (5/100) for Silicon Nitride.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Boron Nitride and Silicon Nitride 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.