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Soda-Lime (Float) Glass

Soda-lime glass is a glass-type material.

The properties of soda-lime glass include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare soda-lime glass to other glass and glass-ceramics (top) and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

Mechanical Properties

Elastic (Young's, Tensile) Modulus

70 to 71 GPa 10 x 106 psi

Knoop Hardness


Poisson's Ratio


Shear Modulus

29 GPa 4.1 x 106 psi

Tensile Strength: Ultimate (UTS)

41 to 180 MPa 5.9 to 25 x 103 psi

Thermal Properties

Maximum Temperature: Mechanical

300 °C 570 °F

Specific Heat Capacity

720 to 800 J/kg-K 0.17 to 0.19 BTU/lb-°F

Thermal Conductivity

1.0 to 1.1 W/m-K 0.58 to 0.61 BTU/h-ft-°F

Thermal Expansion

8.8 to 9.0 µm/m-K

Electrical Properties

Dielectric Constant (Relative Permittivity) At 1 MHz

7.3 to 7.4

Dielectric Strength (Breakdown Potential)

13 kV/mm 0.51 V/mil

Otherwise Unclassified Properties


2.4 g/cm3 150 lb/ft3

Light Transmission Range

0.35 to 2.5 µm

Refractive Index


Common Calculations

Stiffness to Weight: Axial

16 points

Stiffness to Weight: Bending

56 points

Strength to Weight: Axial

4.6 to 20 points

Strength to Weight: Bending

11 to 28 points

Thermal Diffusivity

0.51 to 0.6 mm2/s

Thermal Shock Resistance

4.7 to 20 points

Followup Questions

Further Reading

Glass Construction Manual, Christian Schittich et al., 1999

Dictionary of Glass: Materials and Techniques, Charles Bray, 2002

Glass: Mechanics and Technology, Eric Le Bourhis, 2007