I guess the foreign glass is untempered, or is just junk.
Just to clarify.
Laminated glass and tempered glass are
very different animals.
Standard laminated glass is simply two sheets of normal float/plate glass,which is not tempered in any way with a polycarbonate interlayer creating a three layer sandwich,that's why it can still be cut to shape with a normal diamond tip cutter.
Tempered a.k.a. toughened glass however is a single sheet of float which starts life in much the same way,but once cut to shape and the edges ground it would then go through an additional process in which it's heated to a high temperature and is then cooled rapidly with air jets creating a surface tension in the glass,that's why when it does break it almost 'explodes',it does however remain a single layer.
The theory being small fragments in the event of it breaking in an accident will do you less physical damage than big shards of standard plate glass.
Once this process has been done it
cannot be cut.
If you look at a tempered glass with polarised sun glasses you can sometimes see the stresses.
Laminated glass on the other hand will absorb impact and crack but stay whole relying on the interlayer to provide integrity.
Fwiw a 1/4" thick tempered glass will easily support my 200+lbs weight,a laminated glass of the same thickness wouldn't.
