1864. | Mining, Mineralogy, and Metallurgy. 341 
‘Steel tubes are one of the difficult problems of our hardware manu- 
facture. ‘They are very costly to produce, and very unequal in their 
tenacity when they are turned out, the weld, when the tube is joined down 
the middle, always proving its weakest and almost its unsafe part. Steel 
wires, however, of any thickness or of any fineness, are drawn every day, 
and by a very simple development of the same process a machine has been 
invented by which steel tubes of any thickness or internal diameter can be 
produced with the same certainty. In a few words, it may be said that the 
new method consists of substituting the slow, equal, but irresistible force 
of hydraulic pressure for the ordinarily rapid but somewhat uncertain 
steam power of the wire-drawer’s bench. The whole machinery consists 
of a hydraulic press, with double cylinders placed vis-d-vis with a single 
piston, which as it leaves one cylinder enters the other, and which, at its 
junction between the two, carries a powerful collar or flange of iron. To 
this flange the steel tube to be drawn out is secured-in a die or gauge of 
the requisite shape, while down inside the tube itself passes a steel rod, 
which fits into the circle of the die or gauge, just allowing the requisite 
aperture round its circumference to regulate the size of the tube drawn 
over it. Thus, when once the machine is set in motion by its pump, the 
tube, held by its outer collar, is slowly drawn over the inner rod, which, 
according to its thickness, reduces the tube by pressure against the outer 
die to any fineness, and therefore to any length that may be required. 
Several tubes were thus drawn yesterday in the presence of a number of 
engineers and scientific gentlemen at Mr. Almond’s works, Willow Walk, 
Bermondsey ; and the results, both as to the mechanical trueness of the 
tube and its perfect homogeneousness throughout, were in the very highest 
degree satisfactory. Nor is it circular tubes only that can be drawn by 
this process. By altering the shape of the outer die and inner rod to 
square, triangular, or octagon, the same form of tube is produced with 
equal certainty and equal strength, though in order to avoid distressing the 
metal it is only reduced 4, of an inch at each passage through the machine. 
The movement is so slow that the tube comes out almost cold, yet burnished 
like the finest steel inside and out. The great pressure, however, to which 
it is subjected has a tendency to harden the metal, so that when many 
reductions of size are necessary, it has to undergo annealing to keep it at 
the required toughness. After being drawn to whatever shape or length 
is required, the finished tube can be tempered up to any degree of hard- 
ness, or annealed down to its strongest stage of toughness as may be 
wanted. The whole process is neither an invention nor a discovery, but 
simply a most valuable development of our present means of manufacture.” 
We understand that there are scarcely any limits to the sizes of which 
the tubes can be drawn. Within all the ordinary requirements of our 
engineers, drawn-steel tubes can now be supplied. 
VOL. I. 2A 
