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LiNbO3 vs Sapphire

Glass · grade comparison

LiNbO3 and Sapphire are both glass grades. Sapphire is the stronger of the two: tensile strength 400 MPa (58 ksi) against 100 MPa (14.5 ksi) for LiNbO3, about 4.0 times as much. Sapphire is harder — 2,000 HV against 600 HV for LiNbO3 — which matters for wear surfaces and threads. Sapphire is lighter (3.98 g/cm³ vs 4.65 g/cm³ for LiNbO3) and Sapphire is stiffer (400 GPa vs 175 GPa). On the shop floor, Sapphire sits in a lower cost tier (standard, $$) than LiNbO3 (high, $$$$).

SapphireChoose it when strength drives the design, or when surface hardness matters.

LiNbO3 vs Sapphire: properties

LiNbO3Sapphire

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

175 GPa25.4 Msi
400 GPa58 Msi

Shear Modulus

70 GPa10.2 Msi
148 GPa21.5 Msi

Bulk Modulus

118 GPa17.1 Msi
250 GPa36.3 Msi

Poisson's Ratio

0.25
0.27

Tensile Strength (Ultimate)

100 MPa14.5 ksi
400 MPa58 ksi

Compressive Strength

1,000 MPa145 ksi
2,000 MPa290 ksi

Flexural Strength

120 MPa17.4 ksi
760 MPa110 ksi

Fracture Toughness (K_IC)

1.1 MPa·√m1 ksi·√in
2.2 MPa·√m2 ksi·√in

Hardness, Vickers

600 HV
2,000 HV

Hardness, Knoop

600 HK
2,000 HK

Hardness, Mohs

5
9

Shear Strength

—
350 MPa50.8 ksi

Same in both: Elongation at Break 0%

Physical

Density and transition temperatures.

Density

4.65 g/cm³0.17 lb/in³
3.98 g/cm³0.14 lb/in³

Melting Point (Solidus)

1,257°C2,295 °F
2,053°C3,727 °F

Refractive Index

2.286
1.768

Light Transmission

71%
85%

Same in both: Porosity 0%

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

4.6 W/m·K2.7 BTU/hr·ft·°F
27 W/m·K15.6 BTU/hr·ft·°F

Specific Heat Capacity

628 J/kg·K0.15 BTU/lb·°F
761 J/kg·K0.18 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

15.4 µm/m·K8.6 µin/in·°F
5.8 µm/m·K3.2 µin/in·°F

Max Service Temperature (continuous)

500°C932 °F
1,800°C3,272 °F

Same in both: Min Service Temperature -269°C-452 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹³ Ω·m3.94×10²⁰ µΩ·in
1×10¹⁴ Ω·m3.94×10²¹ µΩ·in

Dielectric Constant (1 MHz)

30
9.8

Dissipation Factor (1 MHz)

0.001
1×10⁻⁴

Volume Resistivity

1×10¹⁵ Ω·cm
1×10¹⁶ Ω·cm

Dielectric Strength

—
17 kV/mm432 V/mil

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

80 / 100
95 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

12 / 100
5 / 100

Polishability

92 / 100
98 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

900 MJ/kg386,931 BTU/lb
400 MJ/kg171,969 BTU/lb

Typical Recycled Content

0%
5%

Embodied Water

—
250 L/kg30 gal/lb

Same in both: Embodied Carbon (primary production) 60 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

22 kN·m/kg
101 kN·m/kg

Specific Stiffness (E / density)

37.6 MN·m/kg
100.5 MN·m/kg

Thermal Diffusivity

1.6 mm²/s
8.9 mm²/s

Thermal Shock Resistance Index

0
5

Strength versus weight

Yield strength against density for every glass grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

501002005002.533.5Density (g/cm³)Yield strength (MPa) — log scaleSapphire

Manufacturing and finishing

CapabilityLiNbO3Sapphire
Default condition—Annealed Glass
Relative cost$$$$ High$$ Standard
Min. machined wall——
Best machined surface——

LiNbO3 vs Sapphire — frequently asked

Is Sapphire stronger than LiNbO3?

Yes. Sapphire has a typical tensile strength of 400 MPa (58 ksi) against 100 MPa (14.5 ksi) for LiNbO3 — about 4.0 times as much.

Which is cheaper, LiNbO3 or Sapphire?

Sapphire is the lower-cost material: it sits in the standard tier ($$) while LiNbO3 is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, LiNbO3 or Sapphire?

LiNbO3, by a small margin. Both rate not recommended for machinability — 12/100 against 5/100 for Sapphire.

Ready to make it?

Upload a CAD file and FabDigit prices the part in LiNbO3 and Sapphire 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.