A Standard Method of Determining Stresses in Glass-to-Metal Seals of the Sandwich and Bead Types

JSGT 1949 V33 T077-T081

The measurement of the stresses in sandwich seals and bead seals of glasses and metals is in common use in valve and lamp manufacture for the routine control of the uniformity of glass- and metal-sealing properties. In such routine tests it is often appropriate to use the metal in the same sheet thickness or wire diameter as is employed in production. If, however, the aim is to make a general estimate of the degree of “match” between various glasses and metals, without reference to a particular single application, and when comparison of results between several laboratories is desirable, there is need for the seals to be of standardised dimensions, and also for the methods of determining the stresses to be standardised. The method now described provides these standards for reasonably matched combinations of glass and metal.

A report of the Society’s Committee on Glass: Manufacture and Properties