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Technical Data

Clear fused quartz glass is a unique material with an unrivalled combination of purity, high temperature resistance, thermal shock resistance, high electrical insulation, optical transparency and chemical inertness.


Density 2.20 x 103 Kg/m3
Youngs Modulus 74 x 106 KN/m2
Rigidity Modulus 32 x 106 KN/m2
Compresive Strength 20 x 106 KN/m2
Tensile Strength 70 x 103 KN/m2
Shear Strength 70 x 103 KN/m2
Moh’s Hardness 6  


Electrical Resistivity 2 x 1019 ohm cm at 20°C
2 x 106 ohm cm at 800°C
Dielectric Strength 10KV/mm at 20°C
2.5KV/mm at 500°C


Strain Point 1385°K
Annealing Point 1455°K
Softening Point 1853°K
Coefficient of Expansion 0.52 x 10-6 per °C
Continuous Operating Temp. >1000°C


Useful Optical Range Synthetic 180 - 2000nm
Natural 275 - 2000nm
Refractive Index nD (589 nm) - 1.458


SiO2 Content 99.995%
Total Metallic Impurities 10ppm (Typical)
Chemical Inertness:
Fused quartz does not react with acids with the exception of hydrofluoric and at high temperatures phosphoric. There is a slow reaction with caustic alkalies at normal temperatures. There is no reaction with water and steam at moderate temperatures and pressures.

More detailed information such as transmission curves and chemical impurity levels are available on request.