Tempered glass
Tempered glass (sometimes referred to as toughened glass) is a type of safety glass that, when it breaks, shatters into small, relatively even pieces that do not have sharp edges. It can also withstand moderate heat.
It is used in situations where large shards of broken glass could cause a hazard, such as in shower doors, frameless glass doors, phone booths, mobile phone screen protectors, diving masks, and car side windows, or in situations where heat may be present, such as in fireplaces.
It is manufactured by a process of extreme heating and rapid cooling, or by a chemical toughening process, that induces compressive stresses in the surface of the glass and tensile stresses in the body of the glass. The internal portion of the glass remain fluid for longer than the outer surfaces during the manufacturing process. This means that an equal amount of tensile and compressive stresses are formed across the glass which allows it to become in the order of four times as strong as annealed glass.
Heat soaked tempered glass may be used in safety critical situations, such as glass railings. Tempered glass panes are heated to a temperature of around 550 degrees Fahrenheit for a few hours. This causes any unstable nickel sulfide inclusions (imperfections that may cause spontaneous breakage of the pane) to expand disproportionately to the glass, making the glass break. Only glass that has not broken is then used.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
About the 5 Percent Club and its members
The 5% Club; a dynamic movement of employers committed to building and developing the workforce.
New Homes in New Ways at the Building Centre
Accelerating the supply of new homes with MMC.
Quality Planning for Micro and Small to Medium Sized Enterprises
A CIOB Academy Technical Information sheet.
A briefing on fall protection systems for designers
A legal requirement and an ethical must.
CIOB Ireland launches manifesto for 2024 General Election
A vision for a sustainable, high-quality built environment that benefits all members of society.
Local leaders gain new powers to support local high streets
High Street Rental Auctions to be introduced from December.
Infrastructure sector posts second gain for October
With a boost for housebuilder and commercial developer contract awards.
Sustainable construction design teams survey
Shaping the Future of Sustainable Design: Your Voice Matters.
COP29; impacts of construction and updates
Amid criticism, open letters and calls for reform.
The properties of conservation rooflights
Things to consider when choosing the right product.
Adapting to meet changing needs.
London Build: A festival of construction
Co-located with the London Build Fire & Security Expo.
Tasked with locating groups of 10,000 homes with opportunity.
Delivering radical reform in the UK energy market
What are the benefits, barriers and underlying principles.
Information Management Initiative IMI
Building sector-transforming capabilities in emerging technologies.
Recent study of UK households reveals chilling home truths
Poor insulation, EPC knowledge and lack of understanding as to what retrofit might offer.