Patent ID: 7562655

Claim:
A matched glass-metal connecting device consisting of a glass tube ( 1 ) and a metal part ( 2 ) fused directly to said glass tube without any intermediary glass material between said metal part and said glass tube, said glass tube ( 1 ) consisting of a glass with a composition, in percent by weight on the basis of oxide content, consisting essentially of: B 2 O 3 8–11.5 Al 2 O 3 5–9 Na 2 O 5–9 K 2 O 0–5 CaO 0.4–1.5 SiO 2 balance to 100%, wherein said composition of said glass comprises less than 400 ppm of iron; and wherein said metal part ( 2 ) is a metal tube consisting of metal material number 1.3981 of DIN 17745; and wherein said metal material has a thermal expansion coefficient that is equal to or about equal to that of said glass.