On Thu, 01 Jan 2004 18:43:06 GMT, "Rick Karlquist N6RK"
wrote:

Correcting misinformation:

Pipe is NOT specified by inside diameter.
It is specified by a "trade size" that is is
associated with a specific outside diameter.
The inside diameter varies, depending on

Yes, this is highly nominal. Trade size is a good way to put that. A
fair amount of variability is possible. At one point, decades ago,
these sizes related to the ID more or less, but enhancements in
materials allowed for thinner walls in the piping, while still using
legacy fittings sized to the outer dimension.

Tubing in various materials, is most often specified by O.D, and then
wall thickness. This includes various metals, aluminum, copper, etc,
rigid plastics like PVC or CPVC, etc, and many of the flexible tubings
out there. Tolerances tend to be much tighter than on pipe. There are
separate series of some tubings in metric.

Various suppliers of tubing and fittings include useful reference info
in their catalogs.

Considering where this was posted, I assume that the OP wants nesting
tubing for making an antenna. If so, see:
http://www.texastowers.com/aluminum.htm

Happy trails,
Gary (net.yogi.bear)
------------------------------------------------
at the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom