[HelloHelp100]

At what temperature does glass shatter?

[Donaldson Tan]

shatter or melt?

[DevaDevil]

And what type of glass?

Normal (window-glass), Pyrex, quartz...

[constant thinker]

"Glass" (it's too broad of a term) will shatter at any temperature. Just take a hammer or other hard object to it with enough force.

[Yggdrasil]

Temperature won't cause glass to shatter, but heating will.

This sounds contradictory, but here's the explanation.  Glass (especially beakers and flasks) can shatter when heating because heating causes the glass to expand.  If the heating is done rapidly and non-uniformly, some areas will expand more than others, putting stress on various areas of the glass.  If this stress gets too strong, it can cause the glass to crack or shatter.  This is especially troublesome for beakers and flasks because of their thin walls (low resistance to stresses) and large surface areas (making them more susceptible to uneven heating).

[constant thinker]

Also remember lab glassware tends to be heated and cooled constantly. The glass will go from room temperature to several 100°F in some applications the cool back down to room temperature. This constant heating and cooling does exactly what Yggdrasil said, and this causes the glass to become more brittle or in some cases to flat out shatter if the glass isn't meant for the temperatures it's at.

[mike]

"Glass" (it's too broad of a term) will shatter at any temperature. Just take a hammer or other hard object to it with enough force.

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