On 8/12/2014 9:36 PM, Doug Miller wrote:
Martin Eastburn wrote in news:PUzGv.194874$ne6.53439
@fx09.iad:

Heating the aluminum tube might expand it more than the thickness of the
metal. If so a hot tube might swallow a dowel and cool skin tight.

No, it won't. Aluminum expands about 12 parts per million per degree Fahrenheit. It would have
to be heated to over 800 degrees F to increase the ID by just 1% -- and that's not nearly
enough to make the ID as large as the room-temperature OD.

We won't even talk about what that would do to the wooden dowel...


What type of expansion is that? Volume ?

Try linear expansion. around the circle. It is a long ring. A ring
will expand more.

Think wagon wheel expanding the wheel band in a fire and then sliding it
onto the oak frame of the wheel. cool with water and it fits tight.

one of the experiments in thermo labs is to take a ring and a ball that
have the same outsides. Heat both in a flame and the ball slides easily
through the ring. Volume is less than linear of the ring.

Martin