Toughened (Tempered) Soda-Lime Glass
Tempered soda-lime glass is a grade of soda-lime glass. The graph bars on the material properties cards below compare tempered 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 GPa 10 x 106 psi
Knoop Hardness
570
Poisson's Ratio
0.23
Shear Modulus
29 GPa 4.1 x 106 psi
Tensile Strength: Ultimate (UTS)
180 MPa 25 x 103 psi
Thermal Properties
Maximum Temperature: Mechanical
300 °C 570 °F
Specific Heat Capacity
720 J/kg-K 0.17 BTU/lb-°F
Thermal Conductivity
1.1 W/m-K 0.61 BTU/h-ft-°F
Thermal Expansion
9.0 µm/m-K
Electrical Properties
Dielectric Constant (Relative Permittivity) At 1 MHz
7.3
Dielectric Strength (Breakdown Potential)
13 kV/mm 0.51 V/mil
Otherwise Unclassified Properties
Density
2.4 g/cm3 150 lb/ft3
Light Transmission Range
0.35 to 2.5 µm
Refractive Index
1.5
Common Calculations
Stiffness to Weight: Axial
16 points
Stiffness to Weight: Bending
56 points
Strength to Weight: Axial
20 points
Strength to Weight: Bending
28 points
Thermal Diffusivity
0.6 mm2/s
Thermal Shock Resistance
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