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Fused Silica vs NaCl

Glass · grade comparison

Fused Silica and NaCl are both glass grades. Fused Silica is the stronger of the two: tensile strength 50 MPa (7.25 ksi) against 3 MPa (0.435 ksi) for NaCl, about 17 times as much. Fused Silica is harder — 700 HV against 20 HV for NaCl — which matters for wear surfaces and threads. Fused Silica is stiffer (72 GPa vs 40 GPa) and Fused Silica runs hotter in service (1,100°C vs 400°C continuous). On the shop floor, NaCl machines more easily (fair vs not recommended) and Fused Silica sits in a lower cost tier (standard, $$) than NaCl (high, $$$$).

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

NaClChoose it when the part is machined in volume.

Fused Silica vs NaCl: properties

Fused SilicaNaCl

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

72 GPa10.4 Msi
40 GPa5.8 Msi

Shear Modulus

31 GPa4.5 Msi
14.9 GPa2.2 Msi

Bulk Modulus

37 GPa5.4 Msi
24 GPa3.5 Msi

Poisson's Ratio

0.17
0.25

Tensile Strength (Ultimate)

50 MPa7.3 ksi
3 MPa0.44 ksi

Elongation at Break

0%
—

Compressive Strength

1,150 MPa167 ksi
25 MPa3.6 ksi

Flexural Strength

67 MPa9.7 ksi
2 MPa0.35 ksi

Shear Strength

30 MPa4.4 ksi
2 MPa0.29 ksi

Fracture Toughness (K_IC)

0.75 MPa·√m0.68 ksi·√in
0.3 MPa·√m0.27 ksi·√in

Hardness, Vickers

700 HV
20 HV

Hardness, Knoop

560 HK
18 HK

Hardness, Mohs

6
2.5

Physical

Density and transition temperatures.

Density

2.2 g/cm³0.08 lb/in³
2.17 g/cm³0.08 lb/in³

Melting Point (Solidus)

1,713°C3,115 °F
801°C1,474 °F

Refractive Index

1.459
1.544

Light Transmission

92%
90%

Same in both: Porosity 0%

Thermal

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

Thermal Conductivity

1.4 W/m·K0.8 BTU/hr·ft·°F
6.5 W/m·K3.8 BTU/hr·ft·°F

Specific Heat Capacity

740 J/kg·K0.18 BTU/lb·°F
854 J/kg·K0.2 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

0.55 µm/m·K0.31 µin/in·°F
44 µm/m·K24.4 µin/in·°F

Max Service Temperature (continuous)

1,100°C2,012 °F
400°C752 °F

Min Service Temperature

-200°C-328 °F
-190°C-310 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹⁶ Ω·m3.94×10²³ µΩ·in
1×10¹² Ω·m3.94×10¹⁹ µΩ·in

Dielectric Strength

30 kV/mm762 V/mil
15 kV/mm381 V/mil

Dielectric Constant (1 MHz)

3.8
5.9

Dissipation Factor (1 MHz)

1×10⁻⁴
5×10⁻⁴

Volume Resistivity

1×10¹⁸ Ω·cm
1×10¹⁴ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

95 / 100
5 / 100

Manufacturability

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

Machinability

10 / 100
45 / 100

Polishability

98 / 100
50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

55 MJ/kg23,646 BTU/lb
20 MJ/kg8,598 BTU/lb

Embodied Carbon (primary production)

4 kg CO₂/kg
1.2 kg CO₂/kg

Embodied Water

80 L/kg9.6 gal/lb
20 L/kg2.4 gal/lb

Typical Recycled Content

0%
20%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

23 kN·m/kg
1 kN·m/kg

Specific Stiffness (E / density)

32.7 MN·m/kg
18.5 MN·m/kg

Thermal Diffusivity

0.8 mm²/s
3.5 mm²/s

Thermal Shock Resistance Index

2
0

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 scaleFused Silica

Manufacturing and finishing

CapabilityFused SilicaNaCl
Default conditionAnnealed Glass—
Relative cost$$ Standard$$$$ High
Min. machined wall——
Best machined surface——

Fused Silica vs NaCl — frequently asked

Is Fused Silica stronger than NaCl?

Yes. Fused Silica has a typical tensile strength of 50 MPa (7.25 ksi) against 3 MPa (0.435 ksi) for NaCl — about 17 times as much.

Which is cheaper, Fused Silica or NaCl?

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

NaCl. Its machinability rates fair (45/100) against not recommended (10/100) for Fused Silica.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Fused Silica and NaCl 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.