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AgBr vs Fused Silica

Glass · grade comparison

AgBr and Fused Silica are both glass grades. Fused Silica is the stronger of the two: tensile strength 50 MPa (7.25 ksi) against 20 MPa (2.9 ksi) for AgBr, about 150% more. In exchange, AgBr is the more ductile: elongation 40% versus 0% for Fused Silica, and Fused Silica is harder (700 HV vs 8 HV). Fused Silica is lighter (2.2 g/cm³ vs 6.47 g/cm³ for AgBr) and Fused Silica is stiffer (72 GPa vs 22 GPa). On the shop floor, AgBr machines more easily (poor vs not recommended) and Fused Silica sits in a lower cost tier (standard, $$) than AgBr (high, $$$$).

AgBrChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

Fused SilicaChoose it when strength drives the design, or when weight is the constraint.

AgBr vs Fused Silica: properties

AgBrFused Silica

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

22 GPa3.2 Msi
72 GPa10.4 Msi

Shear Modulus

8 GPa1.2 Msi
31 GPa4.5 Msi

Bulk Modulus

40 GPa5.8 Msi
37 GPa5.4 Msi

Poisson's Ratio

0.4
0.17

Tensile Strength (Ultimate)

20 MPa2.9 ksi
50 MPa7.3 ksi

Elongation at Break

40%
0%

Compressive Strength

45 MPa6.5 ksi
1,150 MPa167 ksi

Flexural Strength

22 MPa3.2 ksi
67 MPa9.7 ksi

Hardness, Vickers

8 HV
700 HV

Hardness, Knoop

7 HK
560 HK

Hardness, Mohs

1.8
6

Shear Strength

—
30 MPa4.4 ksi

Fracture Toughness (K_IC)

—
0.75 MPa·√m0.68 ksi·√in

Physical

Density and transition temperatures.

Density

6.47 g/cm³0.23 lb/in³
2.2 g/cm³0.08 lb/in³

Melting Point (Solidus)

432°C810 °F
1,713°C3,115 °F

Refractive Index

2.25
1.459

Light Transmission

76%
92%

Same in both: Porosity 0%

Thermal

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

Thermal Conductivity

1.1 W/m·K0.64 BTU/hr·ft·°F
1.4 W/m·K0.8 BTU/hr·ft·°F

Specific Heat Capacity

280 J/kg·K0.07 BTU/lb·°F
740 J/kg·K0.18 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

33 µm/m·K18.3 µin/in·°F
0.55 µm/m·K0.31 µin/in·°F

Max Service Temperature (continuous)

200°C392 °F
1,100°C2,012 °F

Min Service Temperature

-180°C-292 °F
-200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1,000,000 Ω·m3.94×10¹³ µΩ·in
1×10¹⁶ Ω·m3.94×10²³ µΩ·in

Dielectric Constant (1 MHz)

12.5
3.8

Volume Resistivity

1×10⁸ Ω·cm
1×10¹⁸ Ω·cm

Dielectric Strength

—
30 kV/mm762 V/mil

Dissipation Factor (1 MHz)

—
1×10⁻⁴

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

72 / 100
95 / 100

Manufacturability

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

Machinability

30 / 100
10 / 100

Polishability

55 / 100
98 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

900 MJ/kg386,931 BTU/lb
55 MJ/kg23,646 BTU/lb

Embodied Carbon (primary production)

70 kg CO₂/kg
4 kg CO₂/kg

Embodied Water

400 L/kg47.9 gal/lb
80 L/kg9.6 gal/lb

Typical Recycled Content

40%
0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

3 kN·m/kg
23 kN·m/kg

Specific Stiffness (E / density)

3.4 MN·m/kg
32.7 MN·m/kg

Thermal Diffusivity

0.6 mm²/s
0.8 mm²/s

Thermal Shock Resistance Index

0
2

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

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

AgBr vs Fused Silica — frequently asked

Is Fused Silica stronger than AgBr?

Yes. Fused Silica has a typical tensile strength of 50 MPa (7.25 ksi) against 20 MPa (2.9 ksi) for AgBr — about 150% more.

Which is cheaper, AgBr or Fused Silica?

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

AgBr. Its machinability rates poor (30/100) against not recommended (10/100) for Fused Silica.

Ready to make it?

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