On 13-Nov-2003, "Charles Spitzer"
wrote:

Huh? I don't think tempered glass would shatter like you mention.
Safety
glass would, but not tempered glass. It's my understanding that
tempered
glass is designed NOT to shatter and is used in larger window and door
glass, or for glass shelves where higher strength is necessary

then you thunk wrong. you're thinking of safety or laminated glass, which
is
in car windshields. the rest of the car windows are tempered, and can be
shattered by taking a nail and ramming it hard into the glass, preferably
in
an edge. a blunt object (like a wide faced hammer, like the OP used) won't
shatter tempered glass without a good deal of effort. i've seen people
drive
golf balls into tempered glass from short range without any breaks.

Guess I did thunk wrong