Eddie Munster wrote: The heat on the outside will cause the metal to
expand. It isn't a mind reader. It can make the ID smaller. However cold on
the outside will shrink it, causing the ID to increase (you would have to
agree to that, right?
^^^^^^^^^^^^
Wrong! An object, of whatever shape, expands and contracts overall. Any
holes expand at the same rate as the solid parts. This was thoroughly
discussed on the metaloworking newsgroup, and I don't feel like going
through the complete discussion again, but: when a ring expands, the OD,
the ID, the wall thickness, and the hole all expand. It's like an image
being enlarged slightly.