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N-BAK4 vs N-SF11

Glass · grade comparison

N-BAK4 and N-SF11 are both glass grades. N-BAK4 is the stronger of the two: tensile strength 50 MPa (7.25 ksi) against 45 MPa (6.53 ksi) for N-SF11, about 11% more. N-BAK4 is harder — 590 HV against 470 HV for N-SF11 — which matters for wear surfaces and threads. N-BAK4 is lighter (3.1 g/cm³ vs 3.2 g/cm³ for N-SF11) and N-SF11 is stiffer (92 GPa vs 77 GPa). On the shop floor, N-BAK4 machines more easily (28 vs 15 out of 100).

N-BAK4Choose it when strength drives the design, or when surface hardness matters.

N-BAK4 vs N-SF11: properties

N-BAK4N-SF11

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

77 GPa11.2 Msi
92 GPa13.3 Msi

Shear Modulus

31 GPa4.5 Msi
36.6 GPa5.3 Msi

Bulk Modulus

51 GPa7.3 Msi
63 GPa9.1 Msi

Poisson's Ratio

0.25
0.26

Tensile Strength (Ultimate)

50 MPa7.3 ksi
45 MPa6.5 ksi

Flexural Strength

65 MPa9.4 ksi
60 MPa8.7 ksi

Shear Strength

45 MPa6.5 ksi
35 MPa5.1 ksi

Fracture Toughness (K_IC)

0.85 MPa·√m0.77 ksi·√in
0.7 MPa·√m0.64 ksi·√in

Hardness, Vickers

590 HV
470 HV

Hardness, Knoop

600 HK
450 HK

Hardness, Mohs

6
5.5

Same in both: Elongation at Break 0% · Compressive Strength 900 MPa131 ksi

Physical

Density and transition temperatures.

Density

3.1 g/cm³0.11 lb/in³
3.2 g/cm³0.12 lb/in³

Refractive Index

1.569
1.785

Light Transmission

92%
100%

Porosity

—
0%

Thermal

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

Thermal Conductivity

0.85 W/m·K0.49 BTU/hr·ft·°F
0.75 W/m·K0.43 BTU/hr·ft·°F

Specific Heat Capacity

680 J/kg·K0.16 BTU/lb·°F
630 J/kg·K0.15 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

7 µm/m·K3.9 µin/in·°F
8.5 µm/m·K4.7 µin/in·°F

Min Service Temperature

-60°C-76 °F
-200°C-328 °F

Same in both: Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹³ Ω·m3.94×10²⁰ µΩ·in
1×10¹² Ω·m3.94×10¹⁹ µΩ·in

Dielectric Constant (1 MHz)

7
—

Volume Resistivity

1×10¹⁵ Ω·cm
1×10¹⁴ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

68 / 100
60 / 100

Manufacturability

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

Machinability

28 / 100
15 / 100

Polishability

93 / 100
85 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

45 MJ/kg19,347 BTU/lb
60 MJ/kg25,795 BTU/lb

Embodied Carbon (primary production)

2.8 kg CO₂/kg
4 kg CO₂/kg

Embodied Water

35 L/kg4.2 gal/lb
30 L/kg3.6 gal/lb

Typical Recycled Content

10%
20%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

16 kN·m/kg
14 kN·m/kg

Specific Stiffness (E / density)

24.8 MN·m/kg
28.8 MN·m/kg

Same in both: Thermal Diffusivity 0.4 mm²/s · Thermal Shock Resistance Index 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 scale

Manufacturing and finishing

CapabilityN-BAK4N-SF11
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

N-BAK4 vs N-SF11 — frequently asked

Is N-BAK4 stronger than N-SF11?

Yes. N-BAK4 has a typical tensile strength of 50 MPa (7.25 ksi) against 45 MPa (6.53 ksi) for N-SF11 — about 11% more.

Which is cheaper, N-BAK4 or N-SF11?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, N-BAK4 or N-SF11?

N-BAK4, by a small margin. Both rate poor for machinability — 28/100 against 15/100 for N-SF11.

Ready to make it?

Upload a CAD file and FabDigit prices the part in N-BAK4 and N-SF11 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.