Boron Nitride vs Sialon
Ceramic · grade comparison
Boron Nitride and Sialon are both ceramic grades. Sialon is the stronger of the two: tensile strength 350 MPa (50.8 ksi) against 35 MPa (5.08 ksi) for Boron Nitride, about 10 times as much. Boron Nitride is lighter (2 g/cm³ vs 3.25 g/cm³ for Sialon) and Sialon is stiffer (288 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.
SialonChoose it when strength drives the design, or when the part sees heat.
Boron Nitride vs Sialon: 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
Hardness, Vickers
Hardness, Knoop
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Refractive Index
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
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 | Sialon |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Boron Nitride vs Sialon — frequently asked
Is Sialon stronger than Boron Nitride?
Yes. Sialon has a typical tensile strength of 350 MPa (50.8 ksi) against 35 MPa (5.08 ksi) for Boron Nitride — about 10 times as much.
Which is cheaper, Boron Nitride or Sialon?
Both sit in the same relative cost tier ($$$$, 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 Sialon?
Boron Nitride. Its machinability rates excellent (85/100) against not recommended (4/100) for Sialon.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Boron Nitride and Sialon 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.