How can a piece of glass not break when hit by steel?
It seems hard to
believe that you can smack a glass panel with a 25mm steel pipe and bend the
pipe, but with Burglar Safe™ glass you really can. When we toughen glass in our
high speed furnace, we are really setting up a compression in the liquid glass.
There is a lot of information
available on the internet that demonstrates the standard increase in strength
from the toughening process. In essence, the glass acts as a liquid even when
solid. If you try to compress a liquid (eg water) you only make it stronger.
When we toughen glass, we heat and then cool it rapidly, making the outside
contract, trying to compress the inside.
Is this glass unbreakable?
No. Burglar Safe™
glass is very difficult to break and this provides some considerable measure of
protection against intruders, however, it is important to state clearly that
no glass is unbreakable. If an intruder hits any surface hard enough with
an object large enough, it must break. It’s a simple law of physics. Like
“bullet proof” glass, there is no such thing. If the bullet is big enough,
there won’t be much left.
So, how much stronger is toughened glass?
The toughening
process will increase the original “strength thickness” a minimum of 3 times.
In other words, a 4mm toughened piece is the equivalent of 12mm non- toughened.
That’s a half inch on the old scale. To make it even harder to break, the glass
is capable of bending to an amazing degree and this “give” ability absorbs most
impacts.
The majority of windows
have only 3 or 4mm standard annealed glass, so when we upgrade with 6mm Burglar
Safe™ glass, the new strength is usually 5 times stronger because of the
increase in thickness as well as the toughening. What was
3 or 4mm immediately becomes at least 18mm “strength thickness”.
What causes spontaneous breakage?
You may have heard
of glass breaking for no apparent reason. This is generally caused by nickel sulphide
inclusion, which is a technical term for the contamination of the glass during
manufacture by a microscopic particle of stainless steel, probably off a
conveyor or stainless steel roller.
Stainless steel is
made with nickel, and nickel shrinks when heated. During the toughening
process, the glass is heated to 650 degrees centigrade and then cooled before
the nickel can expand back to its original size. Later, sometimes years later, the
force that is exerted down at the microscopic level is enough to set off a
chain reaction and the glass “explodes”. Well, sort of. It is extremely rare.
So rare in fact, we would replace a panel for free if it occurred, but we
haven’t seen one yet.
Will this guarantee my place will not be broken into?
No, however, intruders
are generally opportunistic, so if the glass does not give up even after
repeated attacks, they may first look for another way in or more likely, look
for another target altogether. Your neighbours are probably an easier target.
Why not just use a security screen?
Not everyone likes
to live in a jail. In any case, many windows have a security screen only over
the opening part of the window or door. This works well when you want to leave
an opening for the breeze but of course an intruder can simply break the glass
of the adjoining fixed panel to gain access. We are not suggesting you throw
away your existing screens, but you can get some very good protection by
installing glass that fights back.
If there is a fire, how do I get out?
This is really a
problem with security screens. If you already have security screens, it may be
a good idea to change them for ones that unlock. For both safety and
protection, we recommend Burglar Safe™ glass on the outside and a removable
security screen on the inside.
What is the best way to keep intruders out?
Strangely, this
question is rarely asked of us. After repairs at thousands of break-ins over 20
years, we have never seen a break-in where a security screen was fitted to the
inside. We have seen a lot of forced entry where the security was levered off
the window before breaking in, but never a window broken and then the inside
security screen attacked. We guess that’s because the burglar doesn’t want to
attract attention or set off an alarm before he tackles the bigger job of
breaking through the security screen.
What does it cost?
Burglar Safe™ to
suit a large sliding glass window with fixed panel costs about $350 for the 2
panels plus fitting.
They can be fitted
by our installers or your tradesman or handyman with minimal instruction. The
safety glass aspect makes it especially safe for children.
What now?
Get a quote.
To save your time
and ours (and keep costs down) we do all our quotes over the phone or
preferably, by email. We don’t send out sales reps just to quote. In fact, we
don’t have any sales reps at all because we don’t believe our customers need to
be “sold” anything. We are sure you are perfectly capable of deciding if you
want to buy glass.
We do not vary the
quote for minor changes, even reasonably different sizes, so generally, what we
quote, will be the final cost to you. In fact, we pride ourselves in NOT
changing from our original quote if at all possible, even if you make a genuine
mistake in describing your windows.
After we receive your signed off quote and deposit, we send a tradesman to
take the accurate measurements.
About a week or so
later, the tradesman will arrive with your new glass. The job will generally be
completed within 24/48 hours, for smaller homes it is often the same day.
Call or hit email
now while you have all the information in mind.
Between
call 07 4725 4444 or email info@austinglass.com.au
Between
email info@austinglass.com.au
and we will call you (if you want) at your convenience.