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CdTe vs Sapphire

Glass · grade comparison

CdTe and Sapphire are both glass grades. Sapphire is harder — 2,000 HV against 50 HV for CdTe — which matters for wear surfaces and threads. Sapphire is lighter (3.98 g/cm³ vs 5.85 g/cm³ for CdTe) and Sapphire is stiffer (400 GPa vs 37 GPa). On the shop floor, CdTe machines more easily (fair vs not recommended) and Sapphire sits in a lower cost tier (standard, $$) than CdTe (high, $$$$).

CdTeChoose it when the part is machined in volume.

SapphireChoose it when surface hardness matters, or when weight is the constraint.

CdTe vs Sapphire: properties

CdTeSapphire

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

37 GPa5.4 Msi
400 GPa58 Msi

Shear Modulus

13.3 GPa1.9 Msi
148 GPa21.5 Msi

Bulk Modulus

42 GPa6.1 Msi
250 GPa36.3 Msi

Poisson's Ratio

0.41
0.27

Flexural Strength

22 MPa3.2 ksi
760 MPa110 ksi

Fracture Toughness (K_IC)

0.2 MPa·√m0.18 ksi·√in
2.2 MPa·√m2 ksi·√in

Hardness, Vickers

50 HV
2,000 HV

Hardness, Knoop

45 HK
2,000 HK

Hardness, Mohs

2.8
9

Tensile Strength (Ultimate)

—
400 MPa58 ksi

Elongation at Break

—
0%

Compressive Strength

—
2,000 MPa290 ksi

Shear Strength

—
350 MPa50.8 ksi

Physical

Density and transition temperatures.

Density

5.85 g/cm³0.21 lb/in³
3.98 g/cm³0.14 lb/in³

Melting Point (Solidus)

1,092°C1,998 °F
2,053°C3,727 °F

Refractive Index

2.67
1.768

Light Transmission

65%
85%

Same in both: Porosity 0%

Thermal

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

Thermal Conductivity

6.2 W/m·K3.6 BTU/hr·ft·°F
27 W/m·K15.6 BTU/hr·ft·°F

Specific Heat Capacity

210 J/kg·K0.05 BTU/lb·°F
761 J/kg·K0.18 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

5.9 µm/m·K3.3 µin/in·°F
5.8 µm/m·K3.2 µin/in·°F

Max Service Temperature (continuous)

300°C572 °F
1,800°C3,272 °F

Min Service Temperature

-200°C-328 °F
-269°C-452 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10⁷ Ω·m3.94×10¹⁴ µΩ·in
1×10¹⁴ Ω·m3.94×10²¹ µΩ·in

Dielectric Constant (1 MHz)

10.2
9.8

Volume Resistivity

1×10⁹ Ω·cm
1×10¹⁶ Ω·cm

Dielectric Strength

—
17 kV/mm432 V/mil

Dissipation Factor (1 MHz)

—
1×10⁻⁴

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

50 / 100
95 / 100

Manufacturability

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

Machinability

45 / 100
5 / 100

Polishability

80 / 100
98 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

600 MJ/kg257,954 BTU/lb
400 MJ/kg171,969 BTU/lb

Embodied Carbon (primary production)

45 kg CO₂/kg
60 kg CO₂/kg

Typical Recycled Content

15%
5%

Embodied Water

—
250 L/kg30 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Stiffness (E / density)

6.3 MN·m/kg
100.5 MN·m/kg

Thermal Diffusivity

5 mm²/s
8.9 mm²/s

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

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

CdTe vs Sapphire — frequently asked

What is the difference between CdTe and Sapphire?

CdTe and Sapphire are both glass grades. Sapphire is harder — 2,000 HV against 50 HV for CdTe — which matters for wear surfaces and threads. Sapphire is lighter (3.98 g/cm³ vs 5.85 g/cm³ for CdTe) and Sapphire is stiffer (400 GPa vs 37 GPa).

Which is cheaper, CdTe or Sapphire?

Sapphire is the lower-cost material: it sits in the standard tier ($$) while CdTe is high ($$$$). 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, CdTe or Sapphire?

CdTe. Its machinability rates fair (45/100) against not recommended (5/100) for Sapphire.

Ready to make it?

Upload a CAD file and FabDigit prices the part in CdTe 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.