Bullseye produces glasses with a number of different base
compositions. For this reason, all glasses will not have the
same softening, or annealing points. Briefly, the three
primary categories of Bullseye glasses are: transparents,
opalescents, and lead-bearing gold pink transparents.
The relevant temperature data for these glasses are*:
| |
Transparents |
Opals |
Gold
Pink Transparents |
| Strain point: |
920°F (493°C) |
865°F (463°C) |
820°F (438°C) |
| Annealing point: |
990°F (532°C) |
935°F (501°C) |
882°F (472°C) |
| Softening point: |
1250°F (677°C) |
1270°F (688°C) |
1180°F (638°C) |
*As determined by the standard test method for annealing point
and strain point of glass by fiber elongation, ASTM
Designation C336-71, performed at Corning Engineering
Laboratories.
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