Glass / Glazing / Terms / Types

Please see below the four different glass types of glass used in the glass and glazing Industry of Australia today, going from weakest to strongest. 
                                          ( this is not in reference to available colours and patterns ) 
1. Annealed glass is your basic non-impact glass type. It is used in applications where the required wind load is not so high and safety requirements are not a concern. When annealedglass breaks, it breaks in sharp chards.
2. Heat Strengthened glass is also a non-impact glass. It undergoes a “heat treatment” that increases it’s strength to twice that of annealed glass. It is used in similar applications to annealed glass but where the required wind loads are much higher. When heat strengthened glass breaks, it also breaks in chards.

3. Tempered glass is your basic impact glass. It undergoes a more aggressive “treatment” that increases it’s strength to four times that of annealed glass. It is used in “small missile” impact applications typically installed 30 feet or higher above ground and in safeguard applications. When tempered glass breaks, it breaks into very small cubes.

4. Laminated glass is your typical impact glass. It is a combination of two (usually) of the three previously mentioned glass types that are “laminated” together with an interlayer between 

them. It is typically used in “large missile” impact applications installed up to 30 feet above ground. When laminated glass breaks, it breaks based on it’s glass type make-up but is held in place by the interlayer…similar to a car’s windshield.
Glossary of Glass terms

Acid Etching- A process, manly used for glass decoration, where the glass surface is treated with hydrofluoric acid. Acid-etched glass has a distinctive, uniformly smooth and satin-like appearance.

Annealed Glass – During the float glass process, the hot glass is gently cooled in the “annealing lehr”, which releases any internal stresses from the glass to enable the cutting and further processing of the glass post manufacture.

Antique glass – A general term describing a very old piece of glass, perhaps even several centuries old. Glass with an uneven surface texture and bubbles inside, produced using antique methods in order to obtain the appearance of glass made before the development of industrial processes

Anti-reflective glass – Anti-reflective glass is float glass with a specially-designed coating which reflects a very low % of light. It offers maximum transparency and optical clarity, allowing optimum viewing through the glass at all times

Bulletproof Glass – Designed and produced to resist penetration by bullets. Armor plate glass which is more than 60 mm thick and which resists penetration by bullets. Edge-polished- A glass finishing process of polishing edges. 

Double glazing – Two panes of glass enclosing two hermetically-sealed air spaces. 

Edgework – A process consisting of polishing or abrading-scraping the edge of the glazing surface.

Etching – A process of acid etching one side of float glass to obtain a distinctive, uniformly smooth and satin-like appearance. 

Float Glass – A term for perfectly flat, clear glass (basic product). The term “float” glass derives from the production method, introduced in the UK by Sir Alastair Pilkington in the late 1950′s, by which 90% of today’s flat glass is manufactured. 

Frosting – The process of giving a glass surface a matt finish, thus reducing transparency. 
Frosting may be by means of acid treatment (pouring hydrofluoric acid onto the glass), sandblasting, glass film, special glue application and subsequent removal, or mechanical etching with a grinding wheel.

Heat resistant Glass – Glass which has a low coefficient of expansion and which is therefore less liable to thermal shock. 

Interlayer – The term applied to the material used in laminated glass to bond the glass leaves together. 

Laminated glass consists of two or more sheets of glass with one or more viscous plastic layers “sandwiched” between the glass panes. The solid joining of the glasses takes place in a pressurized vessel called an autoclave (similar to an oven). In the autoclave, under simultaneous heating of the already processed layers of glass and special plastic, lamination occurs. When laminated safety glass breaks, the pieces remain attached to the internal plastic layer and the glass remains transparent. 

Laminated glass – Laminated glass is a combination of two or more glass sheets with one or more interlayer’s of plastic (PVB) or resin. In case of breakage, the interlayer holds the fragments together and continues to provide resistance to the passage of persons or objects. 

Low-emittance (low-E) coating-Microscopically – thin coating of metal oxide, which allows the sun’s heat and light to pass trough the glass into the building. At the same time it blocks heat from leaving the room, reducing heat loss considerably.

Obscure Glass – Any type of glass with uneven surfaces which offers light diffusion and privacy. 

Pane – A lite/sheet of glass. 
Patterned glass – Patterned glass presents uneven surfaces with different impressed patterns. 

Plate Glass – Flat glass made by the casting or rolling of molten glass which is then mechanically ground and polished to produce a smooth and transparent sheet. Used in the past to produce higher quality glass, this technology was completely outperformed by the float glass process (mentioned above). 

Safety Glass – Glass which does not disintegrate into sharp and potentially dangerous splinters when it is broken. Safety glass may be produced by laminating (see “laminated glass”) or by tempering (see “tempering”). 

Sandblasting – A method for giving glass surfaces a matt finish either for decoration or to reduce transparency. Compressed air forces the abrasive material through the nozzle of a sandblasting gun and onto the glass surface. The glass is normally placed inside a special cabinet with arm holes, a viewing window and dust extraction facilities. 

Tempered Glass – Tempered (toughened) glass is two or more times stronger than annealed glass. When broken, it shatters into many small fragments, thus preventing major injuries. 

Tempering – Special process of solidification of a glass sheet in order to make it particularly resistant to breakages. The result is a sheet of glass which is two or three times stronger than un-tempered glass and which, upon breakage, shatters into tiny pieces with blunt edges 

Tight size – The actual size of an opening into which glass is to be glazed and is measured from the rebate platform. 

Toughened Glass -(tempered glass) Toughened glass is two or more times stronger than annealed glass. When broken, it shatters into many small fragments which prevent major injuries. 

Translucent – Allowing light to pass through diffusely. 

Transparent – Clear, permitting vision. 

Wired glass – A product in which a wire mesh has been inserted during production. It has an impact resistance similar to that of normal glass, but in case of breakage, the mesh retains the pieces of glass. 


  1. Glass acts an aesthetic purpose and also a utilitarian function. Many designers and architects learn that the mere inclusion of this material to a space& produces enormous advantages.
    Laminated Glass

  2. Great, you provide best information regarding Glass and Mirrors...


Let me know your thoughts, ideas and experiences

© 2012. All Rights Reserved. Design by Biyan Pasau