Glass Code: Corning

7059

Type

Alkali Free Borosilicate

Color

Clear

Principal Use

Optics & electrical substrates

Thermal Expansion

Multiply by 10^-7cm/cm/°C

0 - 300°C.

46. 0

Viscosity Data

This data is subject to normal manufacturing variations.

Strain point °C.

539

Annealing point °C.

639

Softening point °C.

844

Density g/cm³

2.76

Log₁₀ of Volume Resistivity ohm/cm.

250°C

13.1

Dielectric Properties

(1 MHz 20°C)

Dielectric constant

5. 84

Loss factor  %

.10

Refractive index  @

     435.8 nm

     546.1 nm

     643.8 nm

1. 544

1. 534

1. 531

Transmittance (t=O.5mm)

̃70% (320 nm)

̃90% (360 nm)

>90% (380-2200 nm)

Surface Smoothness

. 5 micro inch (typ)

Surface Flatness

. 004 in/in typ