... , anti-high pressure. This company produces of 3.3 high borosilicate glass, with a good appearance, high temperature, resistance strong pressure ... process to complete. This company produces steel of 3.3 borosilicate glass sight glasses 1.7,2.0,3.0,3 ... ): 3.3 ×10-7 K-1Softening temperature:820°C high borosilicate Glass