Optical Glass picture

PYREX® Borosilicate Glass

Special Properties

  • High thermal resistance
  • Low thermal expansion
  • Good thermal shock resistance
  • Thermal expansion matches silicon (anodic bonding)
  • Low specific weight

Typical Applications

  • Substrate for dielectric coatings
  • PYREX Wafers for anodic bonding
  • Sensor substrates
  • Heat shields
  • Neutron absorbers
  • High temperature applications
  • Harsh environments
PYREX raw glass blocks PYREX comes in unpolished glass blocks or as rolled material. It can be sawn, ground, polished and shaped according to customer-specific requirements.

PYREX® is a technical borosilicate glass composition from Corning with excellent thermal properties. A low coefficient of thermal expansion allows a good heat shock resistance and facilitates the use of PYREX glass at high operating temperatures. Wafers made of PYREX are an ideal solution for PYREX raw materialanodic bonding processes, as the thermal coefficient of expansion almost perfectly matches to silicon. A good acid resistance and a high optical transmission over a wide wavelength range make PYREX a versatile material for many different special glass applications. PYREX can be ground, polished and coated according to custom specific requirements.

To request windows or substrates made of PYREX borosilicate glass with your individual dimensions, please click the button below:

Request for PYREX quotation


Show transmission curve of PYREX

Refractive Index

  • nd = 1,474 (588nm)


  • 2,23g/cm3

Coefficient of Thermal Expansion (0-300°C)

  • 32,5 x10-7

Young's Modulus

  • 6400 kg/mm2

Dielectric Constant

  • 4,6 (20°C; 1Mhz)

Loss Factor

  • 0,5% (20°C;1Mhz)

Further detailed specifications on request.

All given details and specifications are mean reference values and are not guaranteed. In addition, please consider our "Notes on technical specifications"