Alumina 96 vs Alumina 99.5
Ceramic · grade comparison
Alumina 96 and Alumina 99.5 are both ceramic grades, both high hardness ceramic. Alumina 99.5 is the stronger of the two: tensile strength 260 MPa (37.7 ksi) against 190 MPa (27.6 ksi) for Alumina 96, about 37% more. Alumina 99.5 is harder — 1,650 HV against 1,150 HV for Alumina 96 — which matters for wear surfaces and threads. Alumina 96 is lighter (3.72 g/cm³ vs 3.9 g/cm³ for Alumina 99.5) and Alumina 99.5 is stiffer (372 GPa vs 300 GPa).
Alumina 96Choose it when weight is the constraint.
Alumina 99.5Choose it when strength drives the design, or when surface hardness matters.
Alumina 96 vs Alumina 99.5: 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)
Elongation at Break
Compressive Strength
Flexural Strength
Shear Strength
Fracture Toughness (K_IC)
Hardness, Vickers
Hardness, Knoop
Same in both: Hardness, Mohs 9
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
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 880 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 7 µm/m·K3.9 µin/in·°F · Min Service Temperature -269°C-452 °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.
Polishability
Sintering / Firing Temperature
Same in both: Machinability 5 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Same in both: Embodied Energy (primary production) 52 MJ/kg22,356 BTU/lb · 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 | Alumina 96 | Alumina 99.5 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$$$ High | $$$$ High |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Alumina 96 vs Alumina 99.5 — frequently asked
Is Alumina 99.5 stronger than Alumina 96?
Yes. Alumina 99.5 has a typical tensile strength of 260 MPa (37.7 ksi) against 190 MPa (27.6 ksi) for Alumina 96 — about 37% more.
Which is cheaper, Alumina 96 or Alumina 99.5?
Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.
When should I choose Alumina 96 over Alumina 99.5?
Pick Alumina 96 when weight is the constraint. Pick Alumina 99.5 when strength drives the design, or when surface hardness matters.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Alumina 96 and Alumina 99.5 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.