High Borosilicate Glass Tubes

Physical data sheet No. Physics performance Numerical Value Unit 1 coefficient of mean linear thermal expansion(20oC;300 oC) 3.3±0.1 10-6 K-1 2 Transformation Temperature 525±15 oC 3 Softening point 820±10 oC 4 Working point 1260±20 oC 5 Density at 20oC 2.23±0.2 g/cm2 6 Mean thermal conductivity(20oC-100oC) 1.2 W/m.K 7 Refractive Index 0.92 l Chemical Composition in approximate weight %( main components) Item . SiO2 B2O3 AL2O3 Na2O +K2O % 81 13 2 3.08 Chemical Data: Hydrolytic resistance at 98oC ISO719-HGB 1 Hydrolytic resistance at 121oC ISO720-HGB 1 water resistance Grade 1 Test method: ISO1776 Acid resistant Class Grade 1