opaque black glass tube

Technological index: 1) Main composition: a) SiO2: 80 ±0.5% b) B2O3: 13 ±0.2% c) Al2O3: 2.4 ±0.2% d) Na2O (+K2O): 4.3 ±0.2% 2) Chemical properties: a) Coefficient of mean linear thermal expansion (20/300 °C): 3.3±0.1 (10-6K-1) b) Transformation temperature: 525±15°C c) Working point: 1,260 ±20°C d) Softening point: 820 ±10°C e) Density at 20°C: 2.23g/cm² f) Hydrolytic resistance at 98°C: ISO719-HGB1 g) Hydrolytic resistance at 121°C: ISO720-HGA1 h) Acid resistance class: ISO1776-1 i) Alkali resistance class: ISO695-A2 tandard length of tubing:1200mm regular stocked rod:4mm(dark blue, clear),6mm,8mm,10mm,12mm,16mm,20mm,30mm Customized sizes: 4-46mm Our regular stocked colored tube:25*4mm,32*3.2mm,32*4mm,38*3.2mm,38*4mm,44*4mm,51*4mm,51*4.8mm (exclusive of clear tubing) customized sizes:OD6mm-300mm Ten colors available: red, pink, green, purple, light/dark blue, yellow, amber, opaque black, transparent black MOQ per size is 1000kg