Does Heating Glass make it expand?

I know that metal expands slightly when heated, I’m wondering if glass is the same. Thanks.

8 Comments

Connie
on February 8th, 2012

yes it can expand and it can shrink- at temps of like 1000-1800F

you see glass atoms prefer to be only 1/4″ high or thick- so if glass starts at 1/8″ thick it will shrink and pull in to be 1/4″ thick – if the glass starts at 3/8″ it will expand to pool out so it is only 1/4″ thick

comprende?
DarkDesire
on February 8th, 2012

it will explode, cause it wont expand, and it will store up all that energy till.. KABOOM =]
Casper
on February 8th, 2012

Glass is a rather distinctive compound and yes, it expands. But when a metal expands, the relative expansitivity both sides are equal. But in the case of glass, for example a Glass cup, if hot water is poured in it, the relative expansitivity is not balanced in and out so the expansion isn’t proper which causes the glass to break.
FootballFan
on February 8th, 2012

of course. havent you ever heard of glass blowing?
Style
on February 8th, 2012

Yes, glass generally expands as it is heated. See the website under Source(s) below, especially the graphs. Most of the website is very technical, but the answer is clearly stated in words near a graph if you read it thoroughly.
DonkeyKong
on February 8th, 2012

obviously. ALL objects expand when they are heated. the only difference is that some can be spotted by the naked eye while some of them cant
StarbucksCoffee
on February 8th, 2012

Common glass such as flint glass expands about the same as metals when heated. A little less expansion than aluminum, but a little more than stainless steel or copper.

However, borosilicate glass also known as Pyrex (TM) expands very little. Much less than most metals. This is why it doesn’t break when exposed to sudden hot and cold changes.
Gerry
on July 4th, 2011

I have an (antique?) glass jar(green) with a glass lid inset. I kept Us silver coins in it. Now after 30 years I can’t get the lid off. Does any one know what I can do to get the lid off without destroying the jar?