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