In article ,
Ziggur wrote:
However, toughened glass is *vastly* stronger than ordinary (or
laminated) under most circumstances - hence its name.

Does it ever occur to you before you post that, although you may be the
group's resident "expert" on expensive power tools, there are some in
here who have moderate knowledge on other specialist topics?

I don't claim to be the group's resident expert on anything. I leave that
sort of claim to others. Sadly, it's often no guarantee of a reply the
average non expert punter can understand.

Which is why I added the comment to your post - which gave the impression
that toughened was no stronger than normal glass, only safer.

Toughened glass has, on average, 4.5 times more resistance to breakage
by impact than normal annealed glass.

So which part of 'vastly' is now wrong?

That resistance is measured by swinging a leather bag filled with lead
shot on the end of a chain at the glass surface. This archaic test is
the current British Standards method. It confirms that if the glass is
impacted by a football or a head or a similarly large object it will
resist breakage by a factor of "up to" 5 times the level for annealed
glass. HOWEVER - most burglars and all glazing professionals know that
this extra strength is limited to these conditions. A hard tap with a
hammer and nail or a jab with a steel bar) near the edge of a toughened
glass pane will cause it to break more easily than an identical blow on
annealed or laminated glass.

Any glass fitted in the conventional manner into a door has near enough
zero security - regardless of type. Indeed, few ordinary doors of any type
will stop a determined burglar.


Bottom line. The OP asked about thickness and the risk of breakage.
SAFETY glass is about SAFETY, not SECURITY. It breaks, but not
dangerously.

Just who's post were you reading? I made absolutely no comment about
security. If you choose to read that into my post, that's your affair.

Join me for a trip around a Pilkington or a Saint Gobain factory and
then we can talk about De Walt on the way home

No thanks. I doubt we speak the same language.

--
*(on a baby-size shirt) "Party -- my crib -- two a.m

Dave Plowman London SW
To e-mail, change noise into sound.