Nelisco, Inc.

Borosilicate glass is a particular type of glass, better known under the brand name Pyrex. It was first developed by German glassmaker Otto Schott in the late 19th century and sold under the brand name "Duran" in 1893. After Corning Glass Works developed Pyrex it became a synonym for borosilicate glass in the English-speaking world.

Pyrex was introduced by Corning Glass Works in 1924. Though borosilicates had been produced before, the name Pyrex is widely used as a synonym for the material. Pyrex is created by adding boron to the traditional glassmaker's "frit" of silicate sand, soda, and ground lime. Since Pyrex melts at a higher temperature than ordinary silicate glass, some new techniques were required to bring Pyrex into industrial production. Borrowing from the welding trade, new burners combining oxygen with natural gas were required.