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Difference between heat-strengthened glass and fully tempered safety glass

  • Source:ORIGINAL
  • Release on :2018-06-13
Heat strengthened glass, also call semi-tempered glass, or half tempered glass; Fully tempered glass, also call reinforced glass, hardened glass, both of them are heat-treated glass, during processing, need to use tempering furnace to heat the annealed float glass to approximate 650ºC and then cooling down, both of them could make from different kinds of raw glass sheets like clear float glass, tinted float glass, reflective float glass, extra clear float glass, low-e coating glass, sandblasted glass, etc. And both of them could use to make laminated glass, insulated glass, etc. But do you know what’s the difference between the heat-strengthened glass and fully tempered safety glass?

When heating the raw float glass to about 650ºC, to make the tempered safety glass, we need to cool it down rapidly, but to make the heat-strengthened glass, we need to cool it down slowly. Based on the producing time, the heat-strengthened glass cost will be higher than the tempered glass cost.

The fully tempered safety glass has a minimum surface compression of 10,000 psi (69MPa), making it approximately four times stronger than annealed glass of the same thickness and configuration. While for the semi-tempered glass, it only has a surface compression between 3,500 and 7,500 psi (24 to 52 MPa), making it approximately twice as strong as annealed glass of the same thickness and configuration.

And after broken, the tempered glass is shattered into small particles which is not sharp, so human harmless, while when the half-tempered glass broken, it doesn’t shatter, but will be into big pieces, not so safe for human beings.

What’s more, heat-treatment can generate subtle roller waves in glass, which are more likely to occur in tempered glass than in heat-strengthened glass, which lead to heat-strengthened glass has better flatness and light transmission than that of tempered glass.

And more, fully tempered glass is safety glass, while heat-strengthened glass is not considered as safety glazing, but fully tempered glass has the risk of self-explosion, while the heat-strengthened glass doesn’t exist this risk.

Based on the different characteristics of the tempered safety glass and heat-strengthened glass, we could know that the fully tempered glass could be used as monolithic safety glass panels, also could be made into tempered laminated glass and tempered insulated glass, use in place where require high security, like shower door glass, balcony glass, railing glass, floor glass, canopy glass, window glass, etc., while the heat-strengthened glass generally won’t use as monolithic glass panels, because of flatness, less optical distortions, won’t fallout glass frames, it is very often to make into heat-strengthened laminated glass or heat-strengthened insulated glass, used as overhead glazing like structural facade glass, curtain wall glass, exterior elevator glass, skylight glass, etc.

Different projects require different glass, should you have any projects or need more details about the different glass, welcome to contact us any time to discuss.

heat-strengthened laminated glass VS fully tempered laminated glass