Optical Glass picture
Home / Products / Technical Glass / PYREX® 7740

PYREX® 7740

Heat-resistant borosilicate glass

Special Properties

  • High-temperature resistance
  • Low expansion coefficient
  • Good shock resistance
  • CTE is an excellent match to silicon
    (important for anodic bonding processes)
  • Low specific weight

Typical Applications

  • Glass substrates for dielectric coatings
  • PYREX® wafers for anodic bonding applications
  • Sensor substrates
  • Heat shields and covers
  • Neutron absorber glass
  • High-temperature environments
  • Material for science & development
  • Harsh Environments
  • Chemical laboratory equipment

Related glass types

PYREX® 7740 borosilicate glass is a special glass composition from Corning with excellent thermal properties. The material is an industry standard since a long time used for the manufacturing of glass wafers and temperature resistant optics. A low coefficient of expansion which is nearly only one-third of what ordinary soda-lime glass materials can offer allows a good heat shock resistance.

PYREX borosilicate glass raw blocks nullspacer Unprocessed PYREX® borosilicate glass materials come in unpolished large glass blocks or as rolled sheet glass. The materials can be sawn, ground, polished, and shaped according to customer-specific requirements.

It facilitates to use of PYREX® glass at a high operating temperature. Glass Wafers made of PYREX 7740 borosilicate glass materials were a standard for the semiconductor industry for a long time and provided a good solution for anodic bonding processes because the thermal coefficient of expansion is close to silicon. A high chemical resistance, which is much better than the one of soda lime glass, and an excellent optical transmission over a wide wavelength PYREX unpolished borosilicate glass raw material from Corningrange make PYREX® borosilicate glass a versatile option for many special glass and optics applications that are not possible with soda lime glass materials. PYREX® glass can be ground, polished, shaped, and coated according to customer specific requirements.

To request a quotation for windows, substrates or other optics made of PYREX® borosilicate glass with individual dimensions, please use the button below:


Request for Quotation


Availability note: The production of PYREX® 7740 brand borosilicate glass materials was discontinued by Corning many years ago. There is no remaining stock existing, so for this glass material quotes aren't possible anymore. Alternatively, we process very similar and superior quality borosilicate glass materials like BOROFLOAT® and MEMpax®  that feature an almost identical glass composition and nearly identical or better characteristics. For high-temperature requirements, please take a look on our quartz glass and fused silica materials page. Please browse through our web site and send us your inquiry. We will be pleased to assist you in the selection of the perfect replacement glass material for PYREX® 7740 borosilicate glass, that perfectly fits your application.


Specifications of PYREX® Borosilicate Glass

Transmissivity of PYREX® 7740

Enlarge transmission curve of PYREX®

Refractive Index

  • nd = 1,474 (588 nm)


  • 2,23 g/cm3

Coefficient of Thermal Expansion (0-300°C)

  • 3,25 x 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 on request.


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

© 1994-2019 Präzisions Glas & Optik GmbH