What is Pryex®?

Pyrex® is a name we all feel comfortable with. It represents quality and in the laboratory glassware industry it is often thought to be the only option acceptable to buyers. It is amazing what the power of branding can do. Corning, Inc. did such a good job that Pyrex® became a genericized trademark for what is also known as borosilicate glass.

Borosilicate glass was developed slightly prior to Corning's take on the substance. It's first brand name was actually Duran®, developed by Otto Schott in the late 19th century. Another brand name currently used to refer to this type of glass is Kimax® which is produced by Kimble Chase.

Borosilicate glass is created by adding boron to the traditional glassmaker's frit of silicate sand, soda and ground lime. The glass produced has a thermal expansion coefficient about one-third that of ordinary glass resulting in a material that is less stressed by temperature gradients and more resistant to breaking. This along with other factors such as chemical damage resistence, refractory properties and physical strength are what make borosilicate glass a good choice for Norell's NMR tubes.