Helpful glass facts


Glass Properties

                                                            Borosilicate                              Quartz

                                                (Pyrex, Kimax, Duran, Simax)


Coefficient of expansion                  32.5                                                  8.0

( x 10-7 cm/cm/°C)


Temperature limits                         230°C (Normal use)                              1000°C

                                                 400°C ( short-term use only)              


Softening Point                             821°C                                                1580°C


Refractive index                            1.474                                                 1.458

(at sodium D line)




How to identify if an unknown glass is borosilicate glass, without leaving the Lab!


Boroslicate glass can be readily identified by its’ refractive index, 1.474

By immersing the glass in a container of a liquid of similar refractive index, the glass will disappear.

Such liquids are:

Mineral oil,

Dry benzene-methanol mixture, 84:16 (v/v) at room temperature,

Anhydrous gycerol


How to identify if an o-ring is viton.


Viton floats in perchloroethylene, if it sinks, it’s not Viton.


Glass Filter Designations

Porosity                                                        Microns

Fine F                                                 4-5.5              

Medium M                                            10-15

Coarse C                                              40-60

Extra Coarse XC                                     170-220

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