Tempered glass (sometimes called "toughened"
glass) is glass that has been treated so that it is
stronger than ordinary glass. Tempered glass can be up to five
or more times stronger than ordinary annealed glass. It is often
intended for bath and shower enclosures, sliding doors, and similar
locations where increased strength is required.
When broken, tempered glass
will break into small pieces with rounded edges, rather than the
sharp edges that occur when regular glass breaks. The small
fragments help make major injury less likely than ordinary glass.
There are two major methods of making
tempered glass: heat treating and chemical strengthening.
In the heat treating process, the glass is cooled rapidly in a
controlled environment. Most kilns do not have the degree of
control necessary to temper glass, so it takes special tempering
Chemical strengthening, the second way to
make tempered glass, involves using a chemical solution to change
the characteristics of the glass so that it becomes stronger and
less likely to shatter. The chemical process is generally used
where a very thin, strong glass is desired; most window glass is
tempered by heat treating rather than chemical strengthening.
here for information on de-tempering glass in the kiln.
Copyright 2006 Brad Walker.
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