Leadless Sealing Glasses

JSGT 1950 V34 T005-T009

In an earlier communication describing sealing glasses, brief reference was made to a glass (C76) suitable for sealing to iron, and to its use in the manufacture of glass-metal inspection windows. J. H. Partridge in his monograph on glass-to-metal seals assumes, not incorrectly, that C76 is of the same type as the glass No. 542 described by A. W. Hull, E. E. Burger & L. Navias. The latter glass, however, contains 30% lead oxide, whereas C76 is entirely free from lead, a difference of some interest, and one which has led to some useful applications.

J. E. Stanworth