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Ultraviolet (UV) Grade Fused Silica

UV grade fused silica is a grade of fused silica. The graph bars on the material properties cards below compare UV grade fused silica 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

Compressive (Crushing) Strength

1100 MPa 160 x 103 psi

Elastic (Young's, Tensile) Modulus

73 GPa 11 x 106 psi

Flexural Strength

67 MPa 9.7 x 103 psi

Knoop Hardness


Poisson's Ratio


Shear Modulus

31 GPa 4.5 x 106 psi

Tensile Strength: Ultimate (UTS)

50 MPa 7.2 x 103 psi

Thermal Properties

Maximum Temperature: Decomposition

1100 °C 2010 °F

Maximum Temperature: Mechanical

1080 °C 1980 °F

Melting Onset (Solidus)

1900 °C 3450 °F

Specific Heat Capacity

720 J/kg-K 0.17 BTU/lb-°F

Thermal Conductivity

1.4 W/m-K 0.79 BTU/h-ft-°F

Thermal Expansion

0.5 µm/m-K

Electrical Properties

Dielectric Constant (Relative Permittivity) At 1 MHz


Dielectric Strength (Breakdown Potential)

30 kV/mm 1.2 V/mil

Electrical Dissipation At 1 MHz


Electrical Resistivity Order of Magnitude

14 10x Ω-m

Otherwise Unclassified Properties


2.2 g/cm3 140 lb/ft3

Light Transmission Range

0.16 to 3.2 µm

Refractive Index


Common Calculations

Stiffness to Weight: Axial

18 points

Stiffness to Weight: Bending

63 points

Strength to Weight: Axial

6.3 points

Strength to Weight: Bending

14 points

Thermal Diffusivity

0.85 mm2/s

Thermal Shock Resistance

97 points

Followup Questions

Further Reading

Ceramic and Glass Materials: Structure, Properties and Processing, James F. Shackelford and Robert H. Doremus (editors), 2008

Glass: Mechanics and Technology, Eric Le Bourhis, 2007

Handbook of Optical Materials, Marvin J. Weber, 2003

Handbook of Optical Constants of Solids, Edward D. Palik (editor), 1998

Ceramics and Composites: Processing Methods, Narottam P. Bansal and Aldo R. Boccaccini (editors), 2012