"Greg O" wrote in message
...

"Don" wrote in message
k.net...


So, are you saying the metal, upon expansion, acts like the hole is not
there, that the whole thing is solid?
Incidently, I know that heating metal up, like pulleys, works because
I've done it.


It may clear it up if you think of a metal ring instead of a pulley. Cut
the metal ring and lay it out flat and heat it up. The length will change
considerably, although at the same proportion as the diameter. If the
metal rod was rolled back into a ring and heated you have the "length"
expanding and pushing against its self causing the hole to get larger.
Although the pulley will expand in all directions, the ring shape causes
the hole to open up when heated.
Confused yet?

LOL
Actually, that was a good explanation, Greg.