cutting tempered glass

Ordering glass can sometimes be tricky. It can arrive in the wrong size or be the wrong shape for the intended space. If this happens, one possible remedy is to cut the piece to your desired size or shape.

But can you — and should you? — cut tempered glass?

Can you cut glass after you temper it?

Tempered glass is a kind of safety glass that is manufactured to ensure that if it breaks, it will crumble into tiny crystalline pieces instead of large shards that can cause harm.

Before you temper glass, it is first cut into the desired shape and size. Once you temper a piece of glass, it is very difficult to cut it again without shattering it. Typically, only professionals with special laser cutters can cut tempered glass.

Various how-to guides will tell you that you can cut tempered glass by first annealing the piece. It involves placing the tempered glass panel into a craft oven or a kiln and heating it to about 900 degrees Fahrenheit and then carefully letting it cool down for eight or nine hours.

What happens when you try to anneal tempered glass?

After you anneal tempered glass, you can successfully score and cut it into the size and shape you’re after. But as Hunker points out, when you anneal tempered glass, you are essentially removing the temper and returning it to its previous state as “ordinary” glass. It will lose its ability to shatter into grain-like pieces and can no longer be considered safety glass.

If the end product of this process is simply a piece of ordinary glass, then you may be better off just using ordinary glass in the first place.