Borosilicate glass is typically formed from silica and boron oxide constituents. Borosilicate glass has very low thermal expansion coefficient which makes resistant thermal shock more so than any common glass.

Borosilicate also has a high softening point of 820 deg C as well as excellent resistance to water, acids, solvents and halogens. However, high concentrated acid such as hydro fluidic acid and alkaline solutions, corrode the glass rapidly.

Application: Borosilicate is used for virtually all modern laboratory glass ware.  This is because of its chemical thermal resistance as well as optical clarity.

Borosilicate is a cheaper and easier alternative to fused quartz. 

 Other uses include:

• HD lamps
• Guitar slides
• High quality flashlights

Working temperature is 400 deg C