Toughened glass (also called tempered glass) is annealed glass that has been heated to about 620°C and then rapidly cooled with high-pressure air. The process puts the outer surface in compression and the core in tension, making the finished glass roughly 4 to 5 times stronger than ordinary annealed glass.
How toughened glass is made
- Annealed glass is cut, edged and drilled to final size, toughened glass cannot be cut after manufacture.
- The panel is heated in a horizontal furnace to around 620°C.
- It is then quenched by jets of cold air on both surfaces simultaneously.
- The outer surface cools and contracts first while the core stays hot, locking the surfaces under compression.
- This residual compression has to be overcome before the glass can break, hence the strength gain.
How it breaks
When toughened glass does fail, the locked-in stress releases instantly and the entire panel shatters into thousands of small, relatively blunt cubes. There are no long sharp shards. This is why it is classified as a safety glass under AS/NZS 2208.
Where toughened glass is used
- Frameless shower screens and bath enclosures
- Kitchen splashbacks behind cooktops
- Glass pool fencing and balustrades
- Frameless glass entry doors and shopfronts
- Glass tabletops and shelving
- Any panel within 500 mm of a floor in a door or sidelight (AS 1288)
Toughened vs laminated
Both are safety glass. Toughened is stronger and shatters into blunt pebbles when it does fail. Laminated is held together by an interlayer even when cracked, it stays in the frame. The right choice depends on whether you need impact strength (toughened) or containment (laminated). See our full comparison.
Limitations
- Cannot be cut or drilled after manufacture, everything must be specified at the order stage.
- Edges and surfaces are vulnerable to nickel sulfide inclusions, which can cause spontaneous breakage years later (rare with modern heat-soak-tested glass).
- Slight optical distortion (“roller wave”) is normal in horizontal-furnace toughened glass.
Australian Standard
Toughened safety glass installed in Australian buildings must be classified as Grade A safety glass to AS/NZS 2208. Installation locations and minimum thicknesses are governed by AS 1288. Every Panther Glass install is signed off against both before we leave site.
Frequently asked questions
Is toughened glass the same as tempered glass?
Yes. Toughened and tempered are different names for the same process. Australia and the UK lean on “toughened”; the US and parts of Asia use “tempered”.
Can toughened glass be cut?
No. Once toughened, glass cannot be re-cut, drilled or notched. Any modification breaks the entire panel. Order to final size with all cutouts specified upfront.
Is toughened glass bulletproof?
No. It is impact-resistant but not bullet-resistant. For ballistic glazing you need a multi-layer laminated assembly designed for that threat level.
How thick should toughened glass be?
Application-dependent. Splashbacks 6 mm, shower screens 10 mm, balustrades 12 mm, pool fencing 12 mm, most shopfronts 10 to 12 mm. AS 1288 specifies the minimums.
Get a quote
Need a quote? Call 02 4722 2787 or email sales@pantherglass.com.au with photos and we will come back the same business day.