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Borofloat 33 vs Soda-Lime Glass

Glass · grade comparison

Borofloat 33 and Soda-Lime Glass are both glass grades. Soda-Lime Glass is the stronger of the two: tensile strength 45 MPa (6.53 ksi) against 35 MPa (5.08 ksi) for Borofloat 33, about 29% more. Soda-Lime Glass is harder — 550 HV against 480 HV for Borofloat 33 — which matters for wear surfaces and threads. Borofloat 33 is lighter (2.23 g/cm³ vs 2.5 g/cm³ for Soda-Lime Glass) and Soda-Lime Glass is stiffer (72 GPa vs 64 GPa). On the shop floor, Soda-Lime Glass sits in a lower cost tier (budget, $) than Borofloat 33 (standard, $$).

Borofloat 33Choose it when weight is the constraint, or when the part sees heat.

Soda-Lime GlassChoose it when strength drives the design, or when surface hardness matters.

Borofloat 33 vs Soda-Lime Glass: properties

Borofloat 33Soda-Lime Glass

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

64 GPa9.3 Msi
72 GPa10.4 Msi

Shear Modulus

26.7 GPa3.9 Msi
29.5 GPa4.3 Msi

Bulk Modulus

36 GPa5.2 Msi
43 GPa6.2 Msi

Poisson's Ratio

0.2
0.22

Tensile Strength (Ultimate)

35 MPa5.1 ksi
45 MPa6.5 ksi

Compressive Strength

1,000 MPa145 ksi
900 MPa131 ksi

Flexural Strength

25 MPa3.6 ksi
45 MPa6.5 ksi

Shear Strength

25 MPa3.6 ksi
—

Fracture Toughness (K_IC)

0.77 MPa·√m0.7 ksi·√in
0.75 MPa·√m0.68 ksi·√in

Hardness, Vickers

480 HV
550 HV

Hardness, Mohs

6
5.5

Same in both: Elongation at Break 0% · Hardness, Knoop 480 HK

Physical

Density and transition temperatures.

Density

2.23 g/cm³0.08 lb/in³
2.5 g/cm³0.09 lb/in³

Refractive Index

1.471
1.52

Light Transmission

92%
90%

Same in both: Porosity 0%

Thermal

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

Thermal Conductivity

1.2 W/m·K0.69 BTU/hr·ft·°F
1 W/m·K0.58 BTU/hr·ft·°F

Specific Heat Capacity

830 J/kg·K0.2 BTU/lb·°F
840 J/kg·K0.2 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

3.3 µm/m·K1.8 µin/in·°F
9 µm/m·K5 µin/in·°F

Max Service Temperature (continuous)

450°C842 °F
110°C230 °F

Min Service Temperature

-196°C-321 °F
-70°C-94 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹³ Ω·m3.94×10²⁰ µΩ·in
1×10¹⁰ Ω·m3.94×10¹⁷ µΩ·in

Dielectric Strength

30 kV/mm762 V/mil
12 kV/mm305 V/mil

Dielectric Constant (1 MHz)

4.6
7.2

Dissipation Factor (1 MHz)

0.0037
0.009

Volume Resistivity

1×10¹⁵ Ω·cm
1×10¹² Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

92 / 100
85 / 100

Manufacturability

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

Machinability

12 / 100
20 / 100

Same in both: Polishability 95 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
15 MJ/kg6,449 BTU/lb

Embodied Carbon (primary production)

1.8 kg CO₂/kg
1.2 kg CO₂/kg

Embodied Water

15 L/kg1.8 gal/lb
14 L/kg1.7 gal/lb

Typical Recycled Content

10%
22%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

16 kN·m/kg
18 kN·m/kg

Specific Stiffness (E / density)

28.7 MN·m/kg
28.8 MN·m/kg

Thermal Diffusivity

0.6 mm²/s
0.5 mm²/s

Same in both: 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 scaleBorofloat 33

Manufacturing and finishing

CapabilityBorofloat 33Soda-Lime Glass
Default conditionAnnealed Glass—
Relative cost$$ Standard$ Budget
Min. machined wall——
Best machined surface——

Borofloat 33 vs Soda-Lime Glass — frequently asked

Is Soda-Lime Glass stronger than Borofloat 33?

Yes. Soda-Lime Glass has a typical tensile strength of 45 MPa (6.53 ksi) against 35 MPa (5.08 ksi) for Borofloat 33 — about 29% more.

Which is cheaper, Borofloat 33 or Soda-Lime Glass?

Soda-Lime Glass is the lower-cost material: it sits in the budget tier ($) while Borofloat 33 is standard ($$). 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, Borofloat 33 or Soda-Lime Glass?

Soda-Lime Glass. Its machinability rates poor (20/100) against not recommended (12/100) for Borofloat 33.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Borofloat 33 and Soda-Lime Glass 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.