IMPROVEMENTS IN THE MANUFACTURE OF STEEL SHELLS FOR PROJECTILES FOR ORDNANCE
Year: 1877

page_text: LETTERS PATENT to Robert Hadfield, of Sheffield, in the County of York, for
the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF STEEL SHELLS
FOR PROJECTILES FOR ORDNANCE."
Scaled the 19th June 1877, and dated the 6th March 1877.
PROVISIONAL SPECIFICATION left by the said Robert Hadfield at the Office
of the Commissioners of Patents on the 6th March 1877.
ROBERT HADFIELD, of Sheffield, in the County of York. "IMPROVEMENTS IN THE
MANUFACTURE OF STEEL SHELLS FOR PROJECTILES FOR ORDNANCE."
This Invention consists in casting hollow steel shells of a conical or any other
suitable form as circumstances may require. I proceed as follows:-I take either
molten, crucible, Bessemer, Siemens'-Martin, or any other cast steel, the temper and
quality of which render it suitable for the purpose. I then pour such molten metal
into any suitable mould or moulds, preferably made of composition. Such steel
shells when so cast are extremely brittle and of uniform temper throughout, and are
thus perfectly worthless for the purpose of piercing armour plates and other similar
defences. Now to obviate this very great disadvantage I subject such sholls when
cast to an annealing process which reduces the carbon contained therein to any
desired ratio. I then harden and temper the point or apex of such shell as far as
the shoulder or even further if desirable.
By this improved process I obtain a tough and thoroughly homogeneous cast-steel
shell, having an exceedingly hard point or apex which is almost irresistible for the
purpose of penetrating armour plates or other similar defences.
One of the advantages possessed by projectiles manufactured by my improved
process is that the steel is not subjected either to hammering, forging, rolling, or any
other mechanical treatment as hitherto practised.
Another essential feature of my Invention is that the hardening or temper of the
steel is regulated and controlled at will, and by this means a projectile is produced,
apex of which not only possesses an intensely penetrating power, but its rear or
after part also possesses the peculiarly tough and thoroughly homogeneous
characteristics I have before described.
the

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Robert Hadfield in the Great Seal Patent Office on the 5th
September 1877.
ROBERT HADFIELD, of Sheffield, in the County of York. "IMPROVEMENTS IN
THE MANUFACTURE OF STEEL SHELLS FOR PROJECTILES FOR ORDNANCE."
This Invention consists in casting hollow steel shells of a conical or any other
suitable form as circumstances may require, and in order to carry out my Invention
I proceed as follows:-I take either molten, crucible, Bessemer, Siemens'-Martin, or
any other cast steel, the temper and quality of which render it suitable for the
purpose, and pour such molten inetal either into a suitable metallic mould or moulds,
or into a sand or other suitable composition mould or moulds. I cast such shells
hollow and with a suitable plug hole formed in the bottom of each shell for the
purpose of charging the same, thereby dispensing with all necessity for fitting or
attaching the end thereto, as is now practised with forged steel shell, and avoiding
the labour and expense consequent thereon. When so cast such steel shells are of
an extremely brittle and crystalline character and of uniform temper throughout.
They are therefore too brittle for the purpose of piercing armour plates and other
'similar defences. Now to obviate this disadvantage I subject such shells to an
annealing process, which by reducing the carbon contained therein to any desired
ratio, modifies and alters the material by causing a more perfect cohesion of the
particles, and consolidating the atoms or molecules into a dense, close, fine grained
steel, and by eliminating all brittleness therefrom, greatly increases the strength
and density of the shell. I then by any well known method harden and temper
the point or apex of each shell as far as the shoulder, or even farther if desirable.
By this improved process of casting hollow steel shells I obtain an extremely
tough and thoroughly homogeneous cast-steel shell, having an exceedingly hard
point or apex, the penetrating power of which is almost irresistible when employed
against armour plates and other similar defences.
One of the principal advantages possessed by projectiles so manufactured is that
the steel is not subjected either to hammering, forging, rolling, or any other
mechanical treatment as hitherto practised, thus effecting a considerable economy in
the time and labour necessary for their manufacture.
Another essential feature of my Invention is that the hardening or tempering of
the steel may be regulated and controlled at will, and by this means a projectile is
produced, the apex of which not only possesses an intensely penetrating power, but
its rear or after part also possesses the peculiarly tough and thoroughly homo-
geneous characteristics I have before mentioned.
Another considerable advantage of my improved method of casting hollow steel
shells is, that I cast grooves or steps, or other conveniently formed external recesses
or projections, either radial or circumferential, in the base end of such shells in order
to admit of suitable metal, gas checks being either pressed in, or otherwise fastened
and fitted thereto, for the purpose of rotating the shell automatically and facili-
tating its transit, as by this simple method of casting such recesses or projections
therein or thereon, much difficult machine labour is saved, and the necessity of
cutting the same out by costly machinery as is now practised in forged steel shell
is entirely dispensed with, resulting in a very great economy in time, labour, and
expense.
If desired however such shells may be cast without having such external grooves
or projections formed in the base end thereof.
Having now particularly described and ascertained the nature of my said
Invention and the manner of carrying the same into effect, I would have it under-
stood that what I claim is,-
The casting and annealing of hollow steel shells either of a conical or any other
convenient form of an exceedingly tough and thoroughly homogeneous character,

page_text: and possessing an extremely hard point or apex, specially adapted for penetrating
armour plates and other similar defonces, as hercin-before described.
I also claim the casting of a suitable plug hole in the bottom of the shell for the
purpose of charging the same, as herein-before described.
I also claim casting in the base end of such shells, conveniently formed external
grooves, projections, or recesses, for the purpose of suitable gas checks being fitted
thereto, substantially as herein-before described.
In witness whereof, I, the said Robert Hadfield have hereunto set my hand
and seal, this Twenty-eighth day of August, in the year of our Lord One
thousand eight hundred and seventy-seven.
ROBERT HADFIELD. (L.S.)