AN IMPROVED PROCESS OF CONVERTING CAST IRON INTO STEEL APPLICABLE TO THE MANUFACTURE OF EDGE TOOLS
Year: 1873

page_text: LETTERS PATENT to George Haseltine, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the
Invention of "AN IMPROVED PROCESS OF CONVERTING CAST IRON INTO
STEEL APPLICABLE TO THE MANUFACTURE OF EDGE TOOLS."-A communi-
cation from abroad by Thomson Hankey Alexander, of Washington,
District of Columbia, United States of America.
Scaled the 25th July 1873, and dated the 28th January 1873.
PROVISIONAL SPECIFICATION left by the said George Haseltine at
the Office of the Commissioners of Patents, with his Petition, on
the 28th January 1873.
I, GEORGE HASELTINE, of the Firm of Haseltine, Lake, & Co., Patent
5 Agents, Southampton Buildings, London, do hereby declare the nature
of the said Invention for "AN IMPROVED PROCESS OF CONVERTING CAST IRON

page_text: INTO STEEL APPLICABLE TO THE MANUFACTURE OF EDGE TOOLS," a communi-
cation, to be as follows:-
The nature of the said Invention consists in making steel from cast
iron by first making the cast iron partially malleable and then mani-
pulating and temporing the same as herein-after described.
In making edged tools the tool is first made of iron cast in any of the
usual ways and then placed in an annealing furnace. It is kept in this
furnace about two-thirds of the time necessary to make it thoroughly
malleable, that is to say, it remains long enough to remove about two-
thirds of the carbon from the casting. When this has been done the
tool is removed from the annealing furnace, cleaned and hammered into
shape, and about one-eighth of an inch is cut from the entire edge by
means of shears or other suitable instruments. The said tool is then
placed in a heating furnace and brought to a cherry red heat, and then
immersed in water or oil or other tempering liquids used in tempering
stccl. When removed it will be found that the carbon which was
allowed to remain in the tool has been thoroughly scattered or diffused,
and that the partially malleable casting has been converted into steel.
The object of cutting off the edge of the tool is the removal of that
portion of the casting which has become too much decarbonized.
In the manufacture of files the casting, after being removed from the
annealing furnace, has its outer coating or surface, which has been too
much decarbonized, removed, and is then cut and tempered in the usual
manner of making cast steel files. The coating to be removed is very
thin, not being thicker than a sheet of ordinary writing paper. In using
this process it will readily be seen that only so much of the tool is
tempered as is immersed. Thus the handles of files or the cycs of axes
or hatchets remain in a malleable state or soft, and are consequently not
liable to break from sudden blows or in bending.

page_text: "
filed by the said George Haseltine in the Great Seal Patent Office
on the 26th July 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
HASELTINE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of January, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said George Haseltine, Her special licence that
I, the said George Haseltine, my executors, administrators, and assigns,
or such others as I, the said George Haseltine, my executors, adminis-
trators, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein
cxpressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "AN IMPROVED PROCESS OF
CONVERTING CAST IRON INTO STEEL APPLICABLE TO THE MANUFACTURE OF EDGE
Tools," a communication to me from abroad by Thomson Hankey
Alexander, of Washington, District of Columbia, United States of
America, upon the condition (amongst others) that I, the said George
Haseltine, my exccutors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Haseltine, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement :-
-
This Invention consists in converting cast-iron into steel by the
process herein described. By this process objects or articles of cast iron

page_text: are without lusion converted into Succi by iccarbonizing the fron
casting only to such an extent as to retain sufficient carbon to render it
partially malleable, and then manipulating and hardening or tempering
the same in the following manner :-
The said Invention is more particularly described herein as applied to
the making of axes or other edge tools, but it may also be applied to iron
castings for other purposes.
In making edge tools according to this Invention the casting is first
made in any usual manner and then placed in an annealing furnace to be
decarbonized in any suitable manner. I prefer for this purpose to pack
the said casting in a tight fire-brick box with powdered hematite, but I
may adopt any other analagous or suitable method. The casting is
retained in this furnace for a greater or less time, according to the carbon
it contains, until the latter is reduced to the proportion desired for steel,
which is ordinarily about 14 to 14 per cent of carbon, and the time
ordinarily required is about two-thirds of the time necessary to render it
thoroughly malleable or long enough to remove about two-thirds of the
carbon from the casting. When this result has been effected the said
casting is removed from the annealing furnace, cleaned, and restored by
hammering to its shape if necessary, and about one-eighth of an inch is cut
by means of shears or other suitable instruments from the entire edge to
remove that portion of the casting which has been too much decarbonized.
The said casting is then placed in a heating furnace and brought to a
cherry red heat; it is then immersed in water, oil, or other liquid
commonly used or suitable for hardening steel; when the casting is
removed from this liquid it will be found that the carbon which was
allowed to remain in the same has been thoroughly scattered or diffused
through the substance of the metal and that the partially malleable
casting has become converted into steel; the tool can then be finished as
desired.
In the manufacture of files, the casting after being removed from the
annealing furnace has its outer coating, which has been too much
decarbonized (and is ordinarily not thicker than common writing paper)
removed and is then cut and treated in the usual way of making cast stccl
files. In this process the conversion of the cast iron into steel extends
only to the portion of the tool which has been immersed and hardened.

page_text: Thus the handles of files and the eyes of axes or hatchets or similar tools
may be left soft or in a malleable state and consequently will not be
liable to break in bending or from the effect of sudden blows.
Having thus described the said Invention as communicated to me by
my foreign correspondent and the manner of performing the same, I
wish it understood that I claim the hercin described process of converting
articles of cast iron into steel.
In witness whereof, I, the said George Haseltine, have hereunto
set my hand and scal, this Twenty-sixth day of July, in the
year of our Lord One thousand cight hundred and seventy-
three.
Witness,
JAMES EDWARDS,
8, Southampton Buildings,
London.
GEORGE HASELTINE. (L.S.)