PYREX® 7740 – Borosilicate Glass from CORNING®*

Special Properties

  • High-temperature resistance
  • Coefficient of thermal expansion matches that of silicon (important for anodic bonding applications)
  • Good thermal shock resistance
  • Small specific weight
  • Borosilicate glass composition

Typical Applications

  • Glass wafers for anodic bonding
  • Substrates for dielectric coatings
  • Heat shields
  • Chemically resistant glass covers
  • Neutron absorbers
  • High-temperature environments
  • Sensor technology
  • Applications in science, research, and development
  • Harsh Environments
  • Material for chemical laboratory equipment

Related glass types

PYREX® 7740 is a borosilicate glass from CORNING® with excellent thermal properties. A low expansion coefficient of only about one-third of that of soda-lime glass materials ensures high thermal shock resistance. The material has been used to manufacture temperature-resistant optics for a long time.

PYREX® borosilicate glass raw blocks nullspacer

Unprocessed PYREX® 7740 borosilicate glass comes in unpolished large blocks or as rolled sheets. We can grind, polish, and further process these materials to meet customer-specific requirements.

PYREX® 7740 wafers are a standard for the semiconductor industry. They are a perfect solution for the anodic bonding of glass to silicon because the thermal expansion of the PYREX® borosilicate glass closely matches that of silicon.

Unpolished borosilicate glass raw material from CorningA much better chemical resistance than soda-lime materials and exquisite optical transmission over a wide wavelength range made PYREX® 7740 a versatile option for many optical applications that were not possible with ordinary soda-lime glass. For even higher temperature applications, you might be interested in our optical quartz glass materials. For very heat-resistant sight glasses, our fused quartz with sight glass quality could be a solution.

 

Please use the button below to request a quotation for windows, substrates, wafers, or other optics made of PYREX® with individual dimensions.

 

Get a Quote

 

*Important Note:

PYREX® 7740 rolled sheets and block glasses were discontinued many years ago. However, CORNING® meanwhile released a new product called PYREX® Micro-Electro Glass, now available from us in thicknesses of 0.5 mm, 0.7 mm, and 1.1 mm.

 

 

Specifications


PYREX® 7740 Transmission at 2 mm thickness

View larger PYREX® transmission curve

PYREX® 7740 transmission at 2 mm thickness

 

Refractive Index

  • nd = 1.474 (588 nm)

Density

  • 2.23 g/cm3

Coefficient of Thermal Expansion (0–300 °C)

  • 3.25 × 10-6

Young's Modulus

  • 6400 kg/mm2

Dielectric Constant

  • 4.6 (20 °C ; 1 MHz)

Loss Factor

  • 0.5% (20 °C ; 1 MHz)

Further detailed glass specifications are available on request.

All data and specifications given are average guide values and are not guaranteed. Moreover, please consider the “Notes on Specifications”.

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Last update: July 15, 2026