Borosilicate glass was developed in the late 19th century to overcome some specific heat related issues the was a characteristic of standard glass. The inventors discovered that by adding up to 12% Boric Oxide, the coefficient of expansion and its softening point could be dramatically improved. Further developments over the next few decades eventually resulted in a standard material known as borosilicate 3.3 (the 3.3 relating to its coefficient of expansion). This product is now defined within ISO 3585:1998 Standard.
When connecting glass components together it is essential that you ensure that the glass does conform to the same standard as mismatched expansion rates can lead to possible failures.
Unfortunately, not all borosilicate glass manufacturers make their glass to fully adhere to the standard, it can be hard to tell them apart as they appear similar. To ensure your safety and performance of the product it is wise to fully understand the origins and be totally confident that your supplier only offers genuinely compliant products.
Cambridge Glassblowing sources all its raw materials from Europe’s two main glass producers and can, if required, provide certificates of conformity and if essential can even provide batch traceability. When you work with us you can be 100% confident that you only get the genuine article.