- Anneal: To prevent or remove objectionable stresses in glassware by controlled cooling.
- Binder (Fibrous Glass): Substances employed to bond or hold the fibers together.
- Blister: An imperfection a relatively large bubble or gaseous inclusion.
- Check: an imperfection; a surface crack in a glass article.
- Chill Mark: A wrinkled surface condition on glassware, resulting from uneven contact in the mold prior to forming.
- Chip: An imperfection due to breakage of a small fragment from an otherwise regular surface.
- Cord: An unattenuated glassy inclusion, possessing optical and other properties differing from those of the surrounding glass.
- Cullet: waste or broken glass, usually suitable as an addition to raw batch.
- Devitrification: Crystallization in glass.
- Dice: The more or less cubical fracture of tempered glass.
- Fiber: An individual filament made by attenuating molten glass. A continuous filament is a glass fiber of great or indefinite length. A staple fiber is a glass fiber or relatively short length (generally less than 44cm).
- Fusion: Joining by heating.
- Glass Ceramic: A material melted and formed as a glass, then converted largely to a crystalline form by processes of controlled devitrification.
- I.D.: Inside diameter.
- Lampworking: Forming glass articles from tubing and rod by heating in a glass flame.
- Lap: (1) An imperfection; a fold in the surface of a glass article caused by incorrect flow during forming. (2) A process used for mating ground surfaces.
- Liquidus Temperature: The maximum temperature at which equilibrium exists between molten glass and its primary crystalline phase.
- Mat (Fibrous Glass): A layer of intertwined fibers bonded with some resinous material or other adhesive.
- O.D.: Outside diameter.
- Out-of-Round: Asymmetry in round glass articles.
- Sealing: Joining by heating.
- Seed: An extremely small gaseous inclusion in glass.
- Softening Point: the temperature at which a uniform fiber, 0.5 to 1.0mm in diameter and 22.9 cm in length, elongates under its own weight at a rate of 1 mm per minute when the upper 10cm of its length is heated in a prescribed furnace at the rate of approximately 5ºC per minutes. For a glass of density near 2.5, this temperature corresponds to viscosity of 10 • 7.6 poises.
- Standard Taper: A two part number, 24/40, wtih 24 being the approximate diameter in millimeters at the large end of the taper and 40 the axial length of taper, also in millimeters.
- Stone: An imperfection; crystalline contamination in glass.
- Stria: A cord of low intensity generally of interest only in optical glass.
- Tempered Glass: Glass that has been rapidly cooled under rigorous control from near its softening point to increase its mechanical and stermal strength.
- Thermal Endurance: The relative ability of glassware to withstand thermal shock.
- Weathering: Attack of a glass surface by atmospheric elements.
- Working Range: The range of surface temperature in which glass is formed into ware in a specific process. The "upper end: refers to the temperature at which the glass is ready for working (generally corresponding to a viscosity of 10 •3 to 10 •4 poises), while the "lower end" refers to the temperature at which it is sufficiently viscous to hold its formed shape (generally corresponding to a viscosity greater than 10 •6 poises). For compartive purposes, when no specific process is considered, the working range of glass is assumed to correspond to a viscosity range from 10 •4 to 10 • 7.6 poises.
Information courtesy of CORNING