Terminology

Glass Terms and Technical Information

Annealed Glass – This is flat glass from the manufacturer. It generally has a breaking strength of about 500 psi.

Edgework – Annealed glass is not actually cut, but rather cleaved. This leaves a sharp edge that is referred to as "clean cut." This may be acceptable for applications where the glass edge will be enclosed in a frame, but many applications require a fabricated edge.

Distortion – Heat strengthened or fully tempered glass that has been manufactured in a vertical tempering oven contains small surface depressions resembling dimples along one edge. Glass that is passed horizontally through an oven may contain slight surface waves caused by contact with the rollers. This waviness can be detected when viewing reflected images from a distance. Distortion may also be a result of excessive interlayer runnout due to either high temperature lamination and/or pressure created by a vacuum bag during autoclaving.

Heat Strengthened Glass – This is glass that has been subjected to a heating and cooling cycle. It is generally twice as strong as annealed glass of the same thickness and configuration. When broken, the fragments are generally somewhat larger than those for fully tempered glass. This type of glass is intended for general glazing where additional strength is desired but the strength of fully tempered glass is not required.

Tempered Glass – Fully tempered glass is up to five times as strong as annealed glass of the same thickness and configuration. When broken, it breaks into many small fragments of roughly cubical shape. This type of glass is intended for general glazing and safety glazing such as sliding doors, storm doors, building entrances, bath and shower enclosures, counter tops, showcases, interior partitions, and other uses requiring superior strength and
safety properties.

Laminated Glass – Is a sandwich of glass, plastics, and glass. The constituent glasses and plastics can be a variety of colors and thicknesses, and may be mirrored, sandblasted, or stenciled. The interior plastics may also be varied to achieve a desired effect. Laminated glass can be broken, but does not fracture into pieces, instead remaining largely intact. It is used in many safety applications where broken glass shards would be a hazard.

The information contained herein to the best of our knowledge and belief, is accurate. Since the conditions of handling and of use are beyond our control, we make no guarantee of results and assume no liability for damages incurred by following these suggestions. Nothing contained herein is to be construed as a recommendation for use in violation of any patents or of applicable laws of regulations.