... -high temperature, acid, alkali, anti-high pressure. This company produces of 3.3 high borosilicate glass, with a good appearance, high temperature, resistance strong pressure, acid and alkali, high ... :more than test 40Kgf/cm ²Thermal stability:T300 ° CLinear expansion coefficient (0-300 ° C): 3.3 ×10-7 K-1Softening temperature:820°C high borosilicate Glass