Our products include Pharmaceutical neutral glass tube, tubular vial, moulded glass vial, ampoule, rubber stoppers and tear-off caps, Borosilicate clear and colored glass tube and rod, glass cylinder and borofloat glass sheet, and the Lead glass tube, lead free glass tube. Borosilicate Glass 3.3 Tube No. Physics performance Numerical #118alue Unit 1 coefficient of mean linear thermal expansion(20-300 ) 3.3±0.1 10-6K-1 2 Transformation Temperature 525±15 3 Softening point 820±10 4 Working point 1260±20 5 Density at 20 2.23±0.2 g/cm2 6 Mean thermal conductivity(20-100) 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 98 ISO719-HGB 1 Hydrolytic resistance at 121 ISO720-HGB 1 water resistance Grade 1 Test method: ISO1776 Acid resistant Class Grade 1 Test method: ISO1776 Product Feature Borosilicate Glass 3.3 Tube Produced by the international standards strictly