On Sun, 06 Apr 2008 21:28:38 -0400, clare at snyder dot ontario dot
canada wrote:
On Sun, 06 Apr 2008 23:51:58 GMT, Dan@ (Dan ) wrote:

Does this mean there is no such thing as seamless pipe?

No, there IS such a thing as seamless pipe, but it ain't cheap - and
structural tubing is more likely to be DOM

Seamless (SMLS) Steel Pipe is made from a solid round steel ‘billet’
which is heated and pushed or pulled over a form until the steel is
shaped into a hollow tube. The seamless pipe is then finished to
dimensional and wall thickness specifications in sizes from 1/8 inch
to 26 inch OD.

a seamless PIPE is manufactured, for example, from a billet of steel
about 10 inches in diameter and 6 to 8 feet long. After heating to
over 1000 degrees C., a hole is pierced through the center to form a
very thick-walled tube. Hot rolling and cold drawing then
progressively reduces the wall thickness and diameter of this tube
until it is sized for the particular end purpose. Seamless is a costly
method of manufacture; restricted both in size of outside diameter and
in length.

Generally used as boiler tubing.

And no doubt other critical stuff like piping high-pressure
hydraulic systems, high pressure refrigerant to water condensers (dump
the heat to a cooling tower) or evaporators (process water chillers)
or life safety uses like cylinder gases.

If you don't need it, don't specify it - or you have to pay.

-- Bruce --