Curved toughened glass, also known as tempered glass, is manufactured using a fast heating and quenching process. The glass is heated up to 600ºC, curved by oven rollers, and then quenched or cooled rapidly.

This process introduces stresses in the glass, improving its overall material strength.

While not as versatile as annealed curved glass, toughened glass employs a faster production process and enables the use of the best Energy Efficient coatings such as Low-E and High Selectivity coatings. Heat strengthened glass is very similar and produced in the same oven, but quenched more slowly.