Learn more about security glass

There are several different types of glass that are marketed as "security glass" or "safety glass". They all have their pros and cons. Here we answer the most common questions about security glass, safety glass and our products. Feel free to contact us if you do not find an answer to your specific question. If you work with security and real estate in any form, you are warmly welcome to participate in one of our free seminars, where we go through and demonstrate the strengths and weaknesses of different types of glass.


What is Hammerglass®?

Hammerglass® is a durable and optically clear polycarbonate sheet, 300 times stronger than glass – and virtually unbreakable. Hammerglass screens are coated with a hard layer of silicon oxide which protects against scratches and wear and tear. The surface coating also provides 99.96% UV protection, which prevents Hammerglass screens from clouding or becoming discoloured over time. Hammerglass does not contribute to the spread of flames in case of fire.

What is polycarbonate?

Polycarbonate (PC) is a tough, transparent thermoplastic of exceptional durability. Polycarbonate is marketed under the brand names Hammerglass, Lexan, Makrolon, Saphir and more. The difference between the various makes and brands of polycarbonate lies among other things in the purity and surface coatings of the sheets. Without a surface coating PC is easily scratched and will also begin to yellow within six months. Many surface coatings primarily provide protection against yellowing.

What is Plexiglas®?

Plexiglas® is one of several brand names for the acrylic plastic polymethylmethacrylate (PMMA). However, in common parlance the term "plexiglass" is very frequently (and mistakenly) used to refer to plastic sheets in general. Plexiglas® is about 30 times stronger than ordinary glass, but sensitive to scratches and solvents. Plexiglas® will burn.

What is acrylic plastic?

Acrylic plastic is a term for the thermoplastic polymethylmethacrylate (PMMA), which is marketed under trade names such as Bonoplex, Perspex and Plexiglas. Acrylic plastic is sensitive to acids, acetone and other solvents. Acrylic plastic can be distinguished from Hammerglass by the fact that, when prised or subjected to blows, it will crack - unlike Hammerglass which bends without any crack formation. Furthermore acrylic plastic will burn, whereas Hammerglass is self-extinguishing when ignited.

How good is the optical quality of Hammerglass®?

A 12-millimeter Hammerglass window has the same high level of optical quality as windows in helicopters and aircrafts.

What is the heat reduction be with Hammerglass IR?

Hammerglass IR (Infra Red) removes 45-55% of the incoming solar heat.

How to get rid of static electricity?

Static electricity on Hammerglass windows disappears if the windows are washed with water with a little rinse aid (ordinary washing machine rinse aid).

How to order Hammerglass?

Sales are made through resellers, our web shop or Hammerglass AB directly. We are happy to answer questions, and actively participate in the product development of new solutions.


What is safety glass?

Glass which prevents, or actively reduces, the risk of personal injury to those who come into contact with it is designated ‘personal safety glass’, or in practice, ‘safety glass’.
Classification EN 12600 and EN 356, P1A to P3A.

What is security glass?

Glass which protects against vandalism, firearms, trespass, burglary, explosion and blasting, water pressure, electromagnetic radiation, X-rays, fire, noise and UV radiation is designated ’security glass’. Classification EN 356, P6B to P8B.

What is toughened glass?

Toughened glass is up to five times stronger than ordinary glass. When it does eventually break, it disintegrates into an infinite number of small fragments – as anyone who has dropped a sheet of Duralex glass on the floor knows. The fragments are not however sharp-edged, which is why toughened glass is used for the side screens of motor cars. The advantage of toughened glass is that it is relatively cheap and easy to install. The disadvantage is that toughened glass has to be ordered to size since it cannot be cut after toughening has been carried out, and this results in long delivery times. Nor is toughened glass particularly difficult to penetrate. A light blow with a sharp object is often sufficient to break the pane.

What is laminated glass?

Laminated glass consists of two or more glass sheets which have been bonded together with a plastic film. It is also sometimes erroneously referred to as ‘armoured glass’. Laminated glass can be produced as a very thick sheet, which together with the extremely tough interlayer makes it difficult to penetrate – or even, given sufficient thickness, ‘bullet-proof’. However, panes incorporating laminated glass are very expensive to buy and, what is more, difficult to install. The main disadvantage, though, is that laminated glass cracks easily (even though it may hold together in one piece), which renders it an expensive material to use in exposed environments.

What is safety laminated glass?

Ordinary flat glass can be laminated with a safety film on one or both sides. The major advantage of safety lamination is that it is an inexpensive way of making an ordinary glass pane more resistant to knocks and blows. The safety film also prevents glass splinters from being thrown around when the pane breaks up. Application of the safety film can be performed without the glass itself having to be replaced. However, the safety film does not specifically render the pane itself that much stronger. The pane will break under a load which is not that high, and will then have to be replaced (and a new film applied).

What is bullet proof glass?

Bullet resistant glass (bullet proof glass) consists of several glass sheets laminated to resist the power of a bullet. The glass packages often become very thick - 5 cm or more - and therefore also very heavy. Classification EN 1063, BR1 to BR7.


In what security classes and safety classes is Hammerglass available?

Hammerglass unbreakable glazing solutions are available in all the security and safety classes up to P8B, which corresponds to the highest security class for anti-theft grilles and roller shutters. Hammerglass Ballistic Protection is certified in classes BR1-NS, BR4-NS and BR6-NS, Hammerglass Explosion Protection in classes EXR1/EXR2.

How safe are anti-theft grilles and roller shutters?

Unfortunately, many thieves have learned how to remove anti-theft grilles and roller shutters. If a strong rope is attached to a vehicle bumper or tow bar, the anti-theft grille can then be pulled away. Thus, apart from obscuring the view into a shop or display window, anti-theft grilles have in many cases given the shopkeeper or store manager a false sense of security.


What is mechanical crack formation?

Normally, window glass may crack for a variety of reasons. If the glass is incorrectly installed, or if, for example, a screw head lies against the glass, then crack formation may occur. With this type of crack formation, cracks typically grow at irregular angles from the edge of the glass. Contact your installer if such cracks arise.

What is thermal crack formation?

Thermal cracks may arise if the window glass becomes considerably overheated. A thermal crack always proceeds at right angles from the edge of the glass, in contrast to mechanically caused cracks which are formed at irregular angles. Contact your installer if such cracks arise.

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