Toughened Safety Glass | Super Tuff

Key facts

• Super Toughened Glass Ltd (STG) was established in 1999 with the aim of providing tempered glass manufactured to the Kite mark requirement to BS EN 12150.
• Jumbo toughening is tested to BS EN 12150 and BS EN 12600, with a maximum panel size of 6000mm x 3210mm and a thickness range of 4mm to 19mm.
• Heat-strengthened glass has a maximum size of 6000mm x 3210mm and a thickness range of 4mm to 12mm.
• Heat soaked glass is tested to EN 14179, with a maximum size of 6000mm x 3210mm and a thickness range of 4mm to 19mm.
• Toughening service for third-party processed glass covers thicknesses up to 19mm to BS EN 12150 standard.
• Supertuff has three toughening furnaces, including the Glaston FC500, capable of toughening a full jumbo sized sheet.
• Supertuff is located at Glass House Unit 2, 5-9 Willenfield Road, Park Royal, London NW10 7BQ, United Kingdom.
• Tempered glass is manufactured by heating standard annealed (float) glass past its annealing point of around 720°C and then rapidly cooling it.

What is toughened (tempered) glass and how is it made?

Toughened glass, also called tempered glass, is manufactured by Super Tuff by heating standard annealed float glass past its annealing point of around 720°C and then rapidly cooling it. This process transforms the glass so that, in the event of accidental impact, it breaks into small, blunt, relatively harmless pieces rather than large sharp shards, reducing the risk of injury.

What sizes and thicknesses of toughened glass does Super Tuff supply?

Super Tuff's jumbo toughening service produces panels up to a maximum size of 6000mm x 3210mm, in thicknesses ranging from 4mm to 19mm. This is tested to BS EN 12150 and BS EN 12600. The company operates three toughening furnaces, including the Glaston FC500, which is capable of toughening a full jumbo-sized sheet.

What is toughened glass used for?

• Commercial fronts
• Roof glazing
• Balustrades
• Glass doors
• Glass stairs
• Glass floors
• Shower screens

How much stronger is toughened glass than ordinary annealed glass?

Super Tuff states that toughened glass is up to five times stronger than equivalent annealed glass panels. It also offers greater resistance to sudden temperature changes and windy conditions, and the toughening process increases the pane's edge strength, reducing the risk of serious deep cuts if the glass does break.

Can toughened glass be cut, drilled or edged after tempering?

No. Super Tuff can carry out design requirements such as holes, edging or other processing before the tempering process, following discussion with its team ahead of production. Once glass has been toughened it cannot be altered in any way, so any design requirements must be planned and finalised prior to tempering.

What is heat-strengthened glass and when is it used instead of toughened glass?

Heat-strengthened glass is recommended by Super Tuff when glass will be exposed to greater wind loads or higher thermal stress than standard toughened glass is designed for. The process is similar to toughening but with a less rapid cooling cycle, which makes the glass twice as tough as tempered glass while developing less internal stress.

What are the size and thickness limits for Super Tuff's heat-strengthened glass?

Super Tuff's heat-strengthened glass has a maximum size of 6000mm x 3210mm, the same as its jumbo toughened glass, but a narrower thickness range of 4mm to 12mm. It is used for applications such as building facades, laminated skylights, laminated solariums and areas with high wind loads.

Is heat-strengthened glass classed as safety glass?

No. Super Tuff notes that heat-strengthened glass on its own does not meet the criteria of a safety glass product as defined by building regulations and should not be used in critical glazing locations. It does, however, have higher-quality surface characteristics than tempered glass and eliminates the risk of spontaneous breakage from Nickel Sulphide inclusions.

What is heat soaked testing and why does Super Tuff offer it?

Heat soaked testing is an additional process Super Tuff performs on toughened, tempered glass units, under testing method EN 14179, to reduce the risk of spontaneous breakage caused by Nickel Sulphide (NiS) inclusions. NiS is a rare contaminant that can occur during glass manufacture and, in fully tempered glass, can occasionally cause spontaneous breakage.

How does the heat soaking process work?

Super Tuff places tempered glass inside a heat soak chamber and raises the temperature to approximately 290°C. This accelerates the expansion of any Nickel Sulphide inclusions present, causing affected glass to break inside the chamber rather than later in service, reducing the risk of unexpected breakage after installation.

Does heat soaking reduce the strength or appearance of the glass?

No. Super Tuff states that heat soaked glass is still certified as a safety glass and that the strength, appearance and thermal resistance of a toughened glass unit are not reduced by the heat soaking process. Customers are advised to discuss product specifications with their account manager before ordering, as heat soaking is an additional, optional process.

What sizes and applications does Super Tuff's heat soaked glass cover?

• Tested to EN 14179 with reduced risk of spontaneous breakage due to Nickel Sulphide inclusion
• Maximum size: 6000mm x 3210mm
• Thickness range: 4mm to 19mm
• Applications: roof glazing, balustrades, glass doors, glass stairs, glass floors, shower screens, commercial fronts

Can Super Tuff toughen glass that another company has already processed?

Yes. Super Tuff offers a toughening service for glass already cut and processed by other small and medium-sized glass companies, up to 19mm thickness, toughened to the BS EN 12150 standard. The glass is assessed prior to tempering to ensure it meets tempering and regulatory standards.

Where is Super Tuff based?

Super Tuff (Super Toughened Glass Ltd) is based at Glass House Unit 2, 5-9 Willenfield Road, Park Royal, London NW10 7BQ, United Kingdom. The company can be contacted by telephone on 020 8961 8188.

Frequently asked questions

What standards is Super Tuff's toughened glass tested to?

Super Tuff's jumbo toughened glass is tested to BS EN 12150 and BS EN 12600. Heat soaked toughened glass is additionally tested to EN 14179, and the toughening service for third-party processed glass is carried out to the BS EN 12150 standard for thicknesses up to 19mm.

What is the largest panel of toughened glass Super Tuff can produce?

Super Tuff's jumbo toughening service can produce panels up to a maximum size of 6000mm x 3210mm, in thicknesses from 4mm to 19mm, using furnaces including the Glaston FC500, which is capable of toughening a full jumbo-sized sheet.

Is toughened glass considered a safety glazing material?

Yes. Super Tuff states that toughened glass, when broken, shatters into cube-shaped particles rather than sharp shards, which qualifies it as a safety glazing material and helps meet Critical Glazing Building Regulation obligations.

What causes spontaneous breakage in toughened glass, and how does Super Tuff address it?

Spontaneous breakage in toughened glass can occasionally be caused by Nickel Sulphide (NiS) inclusions, a rare contaminant from the glass manufacturing process. Super Tuff offers heat soaked testing, performed to EN 14179, which exposes and breaks affected panels in a controlled chamber before installation, reducing this risk.