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What are the properties of Borosilicate Glass?

What are the properties of Borosilicate Glass?

 Metric US
Coefficient of mean linear thermal3.3 · 10-6 K-1 3.3 · 10-6 K-1
expansion a acc. to DIN ISO 7991(20 °C; 300 °C) (68 °F; 572 °F)
Transformation temperature Tg525 °C 977 °F
Density r at 25 °C2.23 g · cm-3 139.2 lb · ft-3
Modulus of elasticity E (Young’s modulus)63 · 103 N · mm-2 91 · 105 lb · in-2 (psi)
Poisson’s ratio m0.20 0.20
Thermal conductivity lw at 90 °C1.2 W · m-1 · K-1 0.69 Btu · hr -1 · ft-1 · °F-1
Refractive index (l = 587.6 nm) nd1.473 1.473
Stress-optical coefficient (DIN 52 314) K4.0 · 10-6 mm2 · N -1 4.0 · 10-6 mm2 · N-1


Chemical Composition
SiO2 B2O3Na2O +K2O Al2O3
81 134 2

Chemical Resistance
Hydrolytic Class (DIN ISO 719)HGB 1
Acid Class (DIN 12116)Class S 1
Alkali Class (DIN ISO 695)Class A 2