FabDigit

AgBr vs N-BK7 and 2 more: properties

AgBrN-BK7Fused SilicaSapphire

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

22 GPa3.2 Msi
82 GPa11.9 Msi
72 GPa10.4 Msi
400 GPa58 Msi

Shear Modulus

8 GPa1.2 Msi
34 GPa4.9 Msi
31 GPa4.5 Msi
148 GPa21.5 Msi

Bulk Modulus

40 GPa5.8 Msi
47 GPa6.7 Msi
37 GPa5.4 Msi
250 GPa36.3 Msi

Poisson's Ratio

0.4
0.21
0.17
0.27

Tensile Strength (Ultimate)

20 MPa2.9 ksi
50 MPa7.3 ksi
50 MPa7.3 ksi
400 MPa58 ksi

Elongation at Break

40%
0%
0%
0%

Compressive Strength

45 MPa6.5 ksi
1,000 MPa145 ksi
1,150 MPa167 ksi
2,000 MPa290 ksi

Flexural Strength

22 MPa3.2 ksi
65 MPa9.4 ksi
67 MPa9.7 ksi
760 MPa110 ksi

Hardness, Vickers

8 HV
610 HV
700 HV
2,000 HV

Hardness, Knoop

7 HK
610 HK
560 HK
2,000 HK

Hardness, Mohs

1.8
6
6
9

Shear Strength

40 MPa5.8 ksi
30 MPa4.4 ksi
350 MPa50.8 ksi

Fracture Toughness (K_IC)

0.85 MPa·√m0.77 ksi·√in
0.75 MPa·√m0.68 ksi·√in
2.2 MPa·√m2 ksi·√in

Physical

Density and transition temperatures.

Density

6.47 g/cm³0.23 lb/in³
2.51 g/cm³0.09 lb/in³
2.2 g/cm³0.08 lb/in³
3.98 g/cm³0.14 lb/in³

Melting Point (Solidus)

432°C810 °F
1,713°C3,115 °F
2,053°C3,727 °F

Refractive Index

2.25
1.517
1.459
1.768

Light Transmission

76%
92%
92%
85%

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
1.1 W/m·K0.64 BTU/hr·ft·°F
1.4 W/m·K0.8 BTU/hr·ft·°F
27 W/m·K15.6 BTU/hr·ft·°F

Specific Heat Capacity

280 J/kg·K0.07 BTU/lb·°F
858 J/kg·K0.2 BTU/lb·°F
740 J/kg·K0.18 BTU/lb·°F
761 J/kg·K0.18 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

33 µm/m·K18.3 µin/in·°F
7.1 µm/m·K3.9 µin/in·°F
0.55 µm/m·K0.31 µin/in·°F
5.8 µm/m·K3.2 µin/in·°F

Max Service Temperature (continuous)

200°C392 °F
500°C932 °F
1,100°C2,012 °F
1,800°C3,272 °F

Min Service Temperature

-180°C-292 °F
-200°C-328 °F
-200°C-328 °F
-269°C-452 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1,000,000 Ω·m3.94×10¹³ µΩ·in
1×10¹² Ω·m3.94×10¹⁹ µΩ·in
1×10¹⁶ Ω·m3.94×10²³ µΩ·in
1×10¹⁴ Ω·m3.94×10²¹ µΩ·in

Dielectric Constant (1 MHz)

12.5
7
3.8
9.8

Volume Resistivity

1×10⁸ Ω·cm
1×10¹⁴ Ω·cm
1×10¹⁸ Ω·cm
1×10¹⁶ Ω·cm

Dielectric Strength

15 kV/mm381 V/mil
30 kV/mm762 V/mil
17 kV/mm432 V/mil

Dissipation Factor (1 MHz)

1×10⁻⁴
1×10⁻⁴

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

72 / 100
78 / 100
95 / 100
95 / 100

Manufacturability

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

Machinability

30 / 100
18 / 100
10 / 100
5 / 100

Polishability

55 / 100
95 / 100
98 / 100
98 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

900 MJ/kg386,931 BTU/lb
30 MJ/kg12,898 BTU/lb
55 MJ/kg23,646 BTU/lb
400 MJ/kg171,969 BTU/lb

Embodied Carbon (primary production)

70 kg CO₂/kg
2 kg CO₂/kg
4 kg CO₂/kg
60 kg CO₂/kg

Embodied Water

400 L/kg47.9 gal/lb
90 L/kg10.8 gal/lb
80 L/kg9.6 gal/lb
250 L/kg30 gal/lb

Typical Recycled Content

40%
5%
0%
5%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

3 kN·m/kg
20 kN·m/kg
23 kN·m/kg
101 kN·m/kg

Specific Stiffness (E / density)

3.4 MN·m/kg
32.7 MN·m/kg
32.7 MN·m/kg
100.5 MN·m/kg

Thermal Diffusivity

0.6 mm²/s
0.5 mm²/s
0.8 mm²/s
8.9 mm²/s

Thermal Shock Resistance Index

0
0
2
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 scaleN-BK7Fused SilicaSapphire

Manufacturing and finishing

CapabilityAgBrN-BK7Fused SilicaSapphire
Default conditionAnnealed GlassAnnealed GlassAnnealed Glass
Relative cost$$$$ High$$ Standard$$ Standard$$ Standard
Min. machined wall
Best machined surface

Ready to make it?

Upload a CAD file and FabDigit prices the part in AgBr and N-BK7 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.