tempered safety glass Archives - Bear Glass Blog https://bearglassblog.com/tag/tempered-safety-glass/ Wed, 18 Feb 2026 09:40:54 +0000 en-US hourly 1 https://wordpress.org/?v=6.9.4 https://bearglassblog.com/wp-content/uploads/2015/08/cropped-Bear_logo1-1-75x75.png tempered safety glass Archives - Bear Glass Blog https://bearglassblog.com/tag/tempered-safety-glass/ 32 32 Glass Tempering By Bear Glass https://bearglassblog.com/nj-tempering-by-bear-glass/ Thu, 26 Mar 2026 19:49:00 +0000 http://bearglassblog.com/?p=1088 Overview of Tempered Glass: Tempered glass is made using special heated furnaces, which heat the annealed glass to a uniform temperature of approximately 700ºC. When the glass exits the furnace, it is rapidly cooled. This rapid cooling puts the glass surface into a state of compression while the centre core remains in tension. THERMAL TEMPERING Tempering Process:Tempered glass is made by uniformly heating annealed glass to a temperature of up to 700°C and immediately cooling it. The glass first goes through the furnace, carried in by rollers, where it is heated using three modes – conduction, convection and radiation. The rollers conduct the heat, while the coils help in the radiation of heat. The convection effect is brought about by hot air blowing through the nozzles, thus circulating the heat inside the furnace and making sure that the glass is heated evenly on all sides. This super heated glass then undergoes a rapid cooling process by a uniform and simultaneous blast of air on both surfaces. After tempering, the stress pattern developed by the glass is high, and the mechanical strength of tempered glass is four to five times higher than that of annealed glass. Mechanical Strength of Tempered Glass = 4 x Mechanical strength of Annealed Glass When tempered glass is broken, all the stored energy is released at once and the glass breaks into small pieces. Characteristics of Tempered glass: Tempered glass is four to five times stronger than annealed glass of the same size and thickness against impact. Tempered glass has higher thermal strength, and it can withstand high temperature changes up to 250°C. Tempered glass is considered as safety glass. It is difficult to break and even in the event of a breakage, disintegrates into small relatively harmless globules. Tempering does not alter the basic characteristics of glass such as light transmission and solar radiant heat properties of normal glass. The glass surface after heat treatment has the same resistance to surface damage as annealed glass. Tempered glass cannot be cut or altered. One problem that can also exist with tempered glass is spontaneous breakage, where the glass can break for no apparent reason. Spontaneous breakage occurs when nickel sulphide stones increase in size due to repeated heating and cooling. Properties of Tempered Glass: Properties Tempered Glass Thermal Shock Resistance Up to 250°C Mechanical Strength Four to five times stronger thanannealed glass Tensile Strength 65 MPa Bending Strength 120-200 N/mm2 Surface Compression > 95 MPa Design Stress for Architectural Purposes 50 MPa Fragmentation Small round crystals Conducive for Processing Cannot be cut after Tempering Need for Tempered Glass:Tempering increases tensile strength, thermal shock resistance, and safety of normal glass. It also increases its heat withstanding capacity. Because of these properties, tempered glass is preferred in applications where strength, safety and thermal resistance are important considerations. Strength & Safety Considerations Four to five times stronger than annealed glass Two to three times stronger than heat strengthened glass Fragments into small, relatively harmless pieces, reducing the likelihood of injury. Heat resistance Withstands both uneven heating and high temperatures due to its superior edge strength compared to normal annealed glass. Because of its high edge strength tempered glass is used in spider and point fixed glazing. Thermal Breakage:Uneven heating due to direct sunlight makes glass expand and contract at different rates. This difference in the rates of expansion (central part of glass) and contraction (edges of glass) create stresses in glass which may lead to breakage. When temperature difference is below 32°C, the risk of thermal breakage is low, but when the difference becomes more than this, the risk increases significantly. Thermal breakage starts at the edge and is perpendicular to the glass edge. Breakage may be single or multiple depending on the built up stress. Several cracks indicate high thermal stresses across the glass pane. A fully tempered glass has significantly higher edge strength to withstand chances of thermal breakage. Application of Tempered Glass: Tempered glass is specifically designed for use in areas where there is a high risk of contact and breakage. It is not harder or softer than annealed glass but is tougher. Tempering does not make glass more porous nor is tempered glass more prone to scratches than normal glass. Tempered glass offers a wide variety of uses in industries including building, manufacturing, automotive, to name a few. There is a wide scope for the use of tempered glass in the building industry. It can be used to raise the elemental beauty of exteriors and interiors by using it on facades, showroom shelves, dividers, shower cabins, doors and the like. High resistance to thermal stress and small missile impact makes tempered glass an ideal choice for sloped glazing. The manufacturing industry uses tempered glass in ovens, refrigerators, fireplace screens, and shelves. In the motor vehicle industry, tempered glass is commonly used inside and rear windows. To know more about this glass product, contact Bear Glass now!

The post Glass Tempering By Bear Glass appeared first on Bear Glass Blog.

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Overview of Tempered Glass:

Tempered glass is made using special heated furnaces, which heat the annealed glass to a uniform temperature of approximately 700ºC. When the glass exits the furnace, it is rapidly cooled. This rapid cooling puts the glass surface into a state of compression while the centre core remains in tension.

THERMAL TEMPERING

Tempering Process:
Tempered glass is made by uniformly heating annealed glass to a temperature of up to 700°C and immediately cooling it. The glass first goes through the furnace, carried in by rollers, where it is heated using three modes – conduction, convection and radiation. The rollers conduct the heat, while the coils help in the radiation of heat. The convection effect is brought about by hot air blowing through the nozzles, thus circulating the heat inside the furnace and making sure that the glass is heated evenly on all sides. This super heated glass then undergoes a rapid cooling process by a uniform and simultaneous blast of air on both surfaces.


After tempering, the stress pattern developed by the glass is high, and the mechanical strength of tempered glass is four to five times higher than that of annealed glass.

Mechanical Strength of Tempered Glass = 4 x Mechanical strength of Annealed Glass

When tempered glass is broken, all the stored energy is released at once and the glass breaks into small pieces.

Characteristics of Tempered glass:

Tempered glass is four to five times stronger than annealed glass of the same size and thickness against impact.

Tempered glass has higher thermal strength, and it can withstand high temperature changes up to 250°C.

Tempered glass is considered as safety glass. It is difficult to break and even in the event of a breakage, disintegrates into small relatively harmless globules.

Tempering does not alter the basic characteristics of glass such as light transmission and solar radiant heat properties of normal glass.

The glass surface after heat treatment has the same resistance to surface damage as annealed glass.

Tempered glass cannot be cut or altered.

One problem that can also exist with tempered glass is spontaneous breakage, where the glass can break for no apparent reason. Spontaneous breakage occurs when nickel sulphide stones increase in size due to repeated heating and cooling.

Properties of Tempered Glass:








































PropertiesTempered Glass
Thermal Shock ResistanceUp to 250°C
Mechanical StrengthFour to five times stronger than
annealed glass
Tensile Strength65 MPa
Bending Strength120-200 N/mm2
Surface Compression> 95 MPa
Design Stress for Architectural Purposes50 MPa
FragmentationSmall round crystals
Conducive for ProcessingCannot be cut after Tempering

Need for Tempered Glass:
Tempering increases tensile strength, thermal shock resistance, and safety of normal glass. It also increases its heat withstanding capacity. Because of these properties, tempered glass is preferred in applications where strength, safety and thermal resistance are important considerations.


  • Strength & Safety Considerations

    • Four to five times stronger than annealed glass

    • Two to three times stronger than heat strengthened glass

    • Fragments into small, relatively harmless pieces, reducing the likelihood of injury.



  • Heat resistance

    • Withstands both uneven heating and high temperatures due to its superior edge strength compared to normal annealed glass. Because of its high edge strength tempered glass is used in spider and point fixed glazing.

Thermal Breakage:
Uneven heating due to direct sunlight makes glass expand and contract at different rates. This difference in the rates of expansion (central part of glass) and contraction (edges of glass) create stresses in glass which may lead to breakage. When temperature difference is below 32°C, the risk of thermal breakage is low, but when the difference becomes more than this, the risk increases significantly.

Thermal breakage starts at the edge and is perpendicular to the glass edge. Breakage may be single or multiple depending on the built up stress. Several cracks indicate high thermal stresses across the glass pane. A fully tempered glass has significantly higher edge strength to withstand chances of thermal breakage.

Application of Tempered Glass:

Tempered glass is specifically designed for use in areas where there is a high risk of contact and breakage. It is not harder or softer than annealed glass but is tougher. Tempering does not make glass more porous nor is tempered glass more prone to scratches than normal glass. Tempered glass offers a wide variety of uses in industries including building, manufacturing, automotive, to name a few.

There is a wide scope for the use of tempered glass in the building industry. It can be used to raise the elemental beauty of exteriors and interiors by using it on facades, showroom shelves, dividers, shower cabins, doors and the like.

High resistance to thermal stress and small missile impact makes tempered glass an ideal choice for sloped glazing.

The manufacturing industry uses tempered glass in ovens, refrigerators, fireplace screens, and shelves.

In the motor vehicle industry, tempered glass is commonly used inside and rear windows.

To know more about this glass product, contact Bear Glass now!

The post Glass Tempering By Bear Glass appeared first on Bear Glass Blog.

]]> Starphire Glass And Mirror is Cooler Than A Polar Bear https://bearglassblog.com/starphire-glass-and-mirror-is-cooler-than-a-polar-bear/ Tue, 01 Mar 2011 15:21:38 +0000 http://bearglassblog.com/?p=387 ` Bear Glass offers Starphire low iron glass for special production runs, so be sure to ask us about it! Why choose Starphire low iron glass? The difference is clear… Look at “regular” glass and you’ll notice a slight green tint (especially when viewing the edges) that becomes more noticeable when the glass is thicker. Often this is not an issue, but in many applications – such as glass tables and glass table tops, shop windows, entry doors or display cases – clarity becomes more important. And that’s where Starphire low iron glass is clearly better. Starphire low iron glass is specially made for exceptional clarity, and will not dull or distort the true colors in the color spectrum. Whether it’s referred to as “extra clear, ” “water white” or “low iron, ” the glass is made to be crystal clear and virtually tint-free. What makes Starphire low iron glass so pure and sparkling? One of the main ingredients in all glass is silica sand, which has naturally occurring iron oxides. These oxides are what cause the greenish tint in glass. But Starlite low iron glass is made from a high grade of silica sand that is almost completely free of iron oxides. By reducing the iron content you reduce the greenish tint and increase light transmission, brightness and clarity. In fact, Starphire low iron glass can have as little as 10% of the iron content of regular glass, allowing it to transmit 91% of light, compared to 83% for regular glass. Although the raw materials are different, Starphire low iron glass is manufactured the same way as regular glass, and can be pressed, cut, polished, tempered and otherwise worked the same way as well. It can be used wherever regular glass would be used, from interior and exterior applications in commercial buildings, to glass tables and glass table tops. With such a brilliant, beautiful look, Bear Glass wants you to consider Starphire low iron glass for your special orders of glass tables and glass table tops. Characteristics of Starphire glass and mirror Nearly unaltered, neutral, warm reflection Best clarity, truest color, and highest visible light Color purity of desired glass coatings Highest solar energy reflectance of any other acid-etched clear glass We will ship Starphire Glass worldwide. For more information, please contact us at: FACTORY/OFFICE Address: Bear Glass Inc. 399 20th Street Brooklyn, NY 11215 Phone: 718-832-3604 Fax: 718-832-0786 Email: bearglass@yahoo.com

The post Starphire Glass And Mirror is Cooler Than A Polar Bear appeared first on Bear Glass Blog.

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Bear Glass offers Starphire low iron glass for special production runs, so be sure to ask us about it! Why choose Starphire low iron glass? The difference is clear…

Look at “regular” glass and you’ll notice a slight green tint (especially when viewing the edges) that becomes more noticeable when the glass is thicker. Often this is not an issue, but in many applications – such as glass tables and glass table tops, shop windows, entry doors or display cases – clarity becomes more important. And that’s where Starphire low iron glass is clearly better.

Starphire low iron glass is specially made for exceptional clarity, and will not dull or distort the true colors in the color spectrum. Whether it’s referred to as “extra clear, ” “water white” or “low iron, ” the glass is made to be crystal clear and virtually tint-free.

What makes Starphire low iron glass so pure and sparkling? One of the main ingredients in all glass is silica sand, which has naturally occurring iron oxides. These oxides are what cause the greenish tint in glass. But Starlite low iron glass is made from a high grade of silica sand that is almost completely free of iron oxides. By reducing the iron content you reduce the greenish tint and increase light transmission, brightness and clarity.

In fact, Starphire low iron glass can have as little as 10% of the iron content of regular glass, allowing it to transmit 91% of light, compared to 83% for regular glass.

Although the raw materials are different, Starphire low iron glass is manufactured the same way as regular glass, and can be pressed, cut, polished, tempered and otherwise worked the same way as well. It can be used wherever regular glass would be used, from interior and exterior applications in commercial buildings, to glass tables and glass table tops.

With such a brilliant, beautiful look, Bear Glass wants you to consider Starphire low iron glass for your special orders of glass tables and glass table tops.

Characteristics of Starphire glass and mirror

  • Nearly unaltered, neutral, warm reflection
  • Best clarity, truest color, and highest visible light
  • Color purity of desired glass coatings
  • Highest solar energy reflectance of any other acid-etched clear glass

We will ship Starphire Glass worldwide.

For more information, please contact us at:

FACTORY/OFFICE

Address:
Bear Glass Inc.
399 20th Street
Brooklyn, NY 11215
Phone: 718-832-3604
Fax: 718-832-0786
Email: bearglass@yahoo.com

The post Starphire Glass And Mirror is Cooler Than A Polar Bear appeared first on Bear Glass Blog.

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