Standard Clear Quartz Glass EN07

EN07 is mechanically drawn electrically fused clear quartz glass. It uses natural quartz as raw material with SiO2 ≥99.99% (Unimin standard quartz sand). It is available in tube, rod. The tube can also be cut and then rolled into plate.

In lighting: because of its high purity, EN07 has an excellent transmission in both deep UV range of 100-200nm wavelength and UVC range of 200-280nm wavelength. By vacuum annealing, the OH of EN07 can be lowered below 2ppm. So this item is a good material in ozone producing and UVC disinfection field. It is also widely used as the arc tube of long life, high power lamps inside which the pressure is much high.

In semiconductor: the tube is used in diffusion, oxidation and LPCVD process. The rod is used in quartz boat and quartz washing tank. The plate is used in quartz washing tank and so on.

The glass tube can be supplied in the range between 6mm-200mm outer diameter. The rod is available between 1mm-20mm outer diameter. The plate is available of maximum size 650x650x5mm.


Main application is as follows:

Type OH Application
EN07EB OH≤5ppm medium pressure, high pressure ozone producing lamps tube, quality halogen lamps tube, arc tube of high pressure mercury lamps and metal halide lamps, semiconductor diffusion tube and so on.
EN07SB OH≤1ppm medium pressure, high pressure ozone producing lamps tube, arc tube of metal halide lamps.


Chemical Composition:


Al Li K Na Ca Fe Ti Mg Cu B SiO2
EN08Ti 14.0 0.9 0.6 0.9 0.4 0.23 0.6 0.05 0.05 0.08 99.99%


Hydroxyl (OH) Content:

EN08Ti no ≤10 ≤5 ≤1


Thermal Properties:

coefficient of expansion 25-300℃ cm/cm.℃ 5.5 x 10-7
thermal conductivity 20℃ W/m.℃ 1.4
specific heat 20℃ J/Kg.℃ 670
softening point 1680
strain point 1110
annealing point 1200
max. working temperature


Mechanical Properties:

Young’s modulus Pa 7.2 x 1010
density kg/m2 2.2 x 103
tensile strength Pa 4.8 x 107
compressive strength Pa >1.1 x 109
Poisson’s ratio 0.17


Electrical Properties:

loss tangent 20℃ and 1MHz <2 x 10-4
dielectric constant 20℃ and 1MHz 3.75
resistivity 350℃ 7.0 x 109
insulation strength V/m 5.0 x 107


Optical Properties:

index of refraction 1.459
transmittance wall thickness 1.5mm see below form
nm 185 200 220 245 254 320 340 500 800
% 64.8 67.5 84.3 89.8 90.4 92.3 92.4 92.5 92.5

EN07 Graph