For compressive stress with temperatures borosilicate circular sight glass up to max. 280 degrees Celsius,
In a toughened form, temperatures up to 315 degrees Celsius are possible whilst annealed glass may be used up 400 degrees Celsius continuously with a short term maximum of 500 degrees Celsius.
Soda Lime glass according to DIN 8902.
For compressive stress with temperatures borosilicate circular sight glass up to max. 150 degrees Celsius,
This is the most commonly used material due to its low cost. It can be easily toughened to effectively increase the mechanical strength of annealed glass by up to five times.
Quartz glass according to customer's requirements, made from JGS1, JGS2, JGS3, on production.