Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1890-10-11
MANNESMANN TUBE EXHIBIT.

Products Not Seen in This Country-They
Were Turned From Solid Bars of Steel
Can be Twisted and Doubled Without
Affecting the Metal.
On the stage were dozens of samples OF
Mannesmann tubes turned by the famed Ger
man company from solid bars of steel and
able to withstand a pressure OF 5000 pounds
to the square inch. Prof. Wedding de-
livered an interesting lecture on the tubes,
and did it in such an off-hand manner that
there was no question about his familiarity
with the subject. He said:
Some of these are pieces which were closed
at both ends but have been broken in two to
show the forming OF the tube and the massive
block of metal used in its construction. The
interior of the broken parts exhibits a crys-
taline surface with a metallic luster, and
affords incontestable proof of the existence of
vacuum during the formation of the tubes
also of the absence of a mandril, bit or similar
tool. Other samples illustrate the working Of
maudril in its application for smoothing the
crystalline inner sides Of the pipes. A series
of these specimens conclusively prove that the
tubes can be turned out in any desired dimen-
sion.
Several specimens of three and four inch
tubes, of which 80 miles of each size have been
furnished for South American water MAN,
Of the four inch pipes there has been furnished
petroleum residue conduit, Is English miles
in length for the Caucasian district, the oil to
be pumped height of $500 feet to the top of
4 mountain, every piece having before de-
livery, been tested by the buyers to withstand a
pressure OF $500 pounds to the square inch.
These pipes are of. the:ordInary length. l. e.. 16-
% feet; the Mannesmann-tubes have been
turned our, however, IN lengths of 40 feet and
upward, which evidently iusur.s a considerable
decrease in the number of connecting pieces.
The hammered samples of these tubes and
those which have been shortened. also by be-
ing hammered. are evidence of the elasticity of
the pipes and their adaptability for use with
out separate connecting pieces; it being COM
paratiVely easy matter to join the tubes them
selves. Also to convert them into any desired
shape or form for constructive purposes.
Other Mannesnann tubes. which have been
turned inside out and then doubled up, give
evidence that the metal not alone did not suffer
through having been worked by this process
but that on the contrary the quality of the
steel has been improved thereby to a degree
never before attained in any tubular article
Welded tubes. if treated in this manner would
split open, while pipes turned out from massive
blocks by the latter being made hollow through
boring. could not with safety be treated in this
way on account or the absence of the spiral
like 1brous structure. for which the Names
mann tubes are noted. The diameter of some
of The sample pieces has been increased three
fold by forcing comic wedge into their ends,
without using other pressure. This equals a
tensile eloDgation by traction to three times
the original length.
The dream of all bridge builders the thin
walled, weldless steel tube of large diameter
and great length has been realized. We see
parts of the historically interesting first
production of Mannesmann tubes l8 and Is
inches in diameter, with q one-fourth inch
wall. The employment of these tubes in a
larger diameter permits the building of longer
spans OF greater length than has been feasible
i'll the past.