How Much Heat Can Borosilicate Glass Withstand?

Borosilicate glass, renowned for its exceptional thermal resistance, is a specialized type of glass that can withstand significantly higher temperatures than ordinary soda-lime glass. While a typical drinking glass might crack with a temperature shock of just 50-60°C, borosilicate glass is engineered to handle extreme heat and rapid temperature changes.

The key to its performance lies in its chemical composition. It is primarily made from silica ( SiO2) and boron trioxide ( B2O3). The addition of boron reduces the glass's coefficient of thermal expansion, meaning it expands and contracts much less than ordinary glass when heated or cooled. This property is what makes it so resistant to thermal shock.

So, what are the exact numbers? Borosilicate glass can consistently withstand temperatures up to 515°C (959°F). Its maximum service temperature is the point at which it will not deform or soften. More impressively, it can handle rapid thermal shocks with temperature differences ranging from 160 to 200°C (320 to 392°F). This means you can safely take a hot borosilicate glass dish from a 200°C oven and place it on a cool, wet countertop without it shattering.

This incredible durability makes it the material of choice for a vast array of applications. It is used in laboratory glassware (like beakers and flasks), industrial sight glasses, high-quality kitchen bakeware (such as the iconic Pyrex dishes), and even in telescope mirrors. Its ability to remain stable and intact under thermal stress ensures safety, reliability, and longevity in environments where heat is a critical factor.