Borosilikatglas

Physical Property : No. Physical performance Numerical Value Unit 1. Coefficient of mean linear thermal expansion(20,300) 3.30.1 10-6K-1 2. Transformation temperature 52515 3. Softening point 82010 4. Working point 126020 5. Density at 20 2.230.02 g/cm3 6. Mean thermal conductivity(20-100) 1.2 w/m2k 7. Refractive index 0.92 1Main Composition SiO2:81 B2O3 :13 Na2O+K2O :4 Al2O3 :2 Chemical Property : Hydrolytic resistance at 98 ISO719-HGB 1 Hydrolytic resistance at 121 ISO720-HGA 1 Acid resistance Class ISO1776-First Class