IMPROVEMENTS IN THE PRODUCTION OF IRON STEEL AND OTHER METAL CASTINGS
Year: 1884

page_text: PROVISIONAL DIVIFICATION
I, THORSTEN NORDENFELT of 53 Parliament Street in the City of Westminster
Civil Engineer do hereby declare the nature of my invention for "IMPROVEMENTS
IN THE PRODUCTION OF IRON STEEL AND OTHER METAL CASTINGS" A communi-
cation from abroad by Carl Gustaf Wittenström of Motala, Edward Faustman and
Petter Östberg Civil Engineers of Stockholm all in the Kingdom of Sweden to be
as follows:-
This Invention has for its object improvements in the production of iron steel
and other metal castings.
In the production of castings in sand moulds from metals having a high melting
point as iron, and steel and especially iron nearly free from carbon the sand plays a
prominent part for obtaining a good and fine product.
A facing sand in every way suitable has never hitherto been produced... It
should be infusible so that it may not stick to the castings nor act in any way.
injuriously upon the metal.
After many experiments it has been found that hard burned fireclay mixed only!
with binding material and a little liquid hydro-carbon to give a fine surface is the:
most suitable material.
-
-
-
I would bere state that burnt fireclay has sometimes been used as an ingredient
in facing sand employed in the production of fine art castings in bronze, but alwaysi
in admixture with siliceous sand and usually with powdered charcoal.
Now such admixtures do not produce facing sands suitable for use with metals
requiring very high temperatures in the casting operation. The siliceous sand
fluxes the clay causing the sand to adhere to the face of the casting.
Powdered charcoal by combining with the metal tends to alter and deteriorate
the face of the casting especially if of comparatively pure iron or steel and its ash
also tends to render the facing sand less refractory.

page_text: The facing sand the subject of this specification is prepared solely from hard
burned fireclay finely ground with only so much binding substance added as to
make it firm after drying. As binding substances sugar, molasses, gum, glue, raw
clay, etc. etc. can be used but sugar is preferred because it has been found superior,
and it is clean and of equal quality and may be had everywhere. To make the 5
sand leave the castings more easily and give the castings a fine looking surface a
small quantity of keroseno or like hydrocarbon oil is added.
Old furnace bricks of good fire clay well cleaned from glaze or the like give the
best and cheapest sand. The clay ought to be of the most fireproof kind and to be
as free from foreign ingredients as possible and specially from such as are of an 1
alkaline nature.
It has been found that different fireclays require different quantities of binding
substance to give the requisite firmness; the following proportions will generally
be found suitable. One volume white crystallized sugar is dissolved in about two
volumes pure water and strained and then about one eighth of a volume of kerosene 1
or like hydrocarbon oil is added. Twenty four to thirty volumes of hardburned
powdered fireclay is moistened with the foregoing solution and the mass passed
through a coarse sieve several times so as to ensure an equal distribution of the
moisture. This facing sand ought to be as moist as common facing sand and to this
eud-more-water-is-added if necessary, Care should be taken to employ pure 2
materials and especially such as are free from lime and like-impurities_as_these_
even when present in very small proportion injure the face of the castings-
The facing sand the subject of this specification differs in its properties from
every other facing-sand, in the following viz.
1. It is practically infusible and therefore does not stick to the castings which 2
are found loose and clean-when-the-mould is opened, and but insignificant cleaning
--is-required..
2. It does not carburate the castings as any sand containing carbon in any shape
will-do, neither-will it make the castings porous or brittle, as the silicon facing
sand seems to do. The castings will preserve their nature-of-wrought iron_or_steel_3
according to the percentage of carbon in the molten metal.
3. It gives to the castings an exceedingly beautiful light-blue glossy surface.
4. Although fireclay may have been before used as an ingredient in facing sand
the same results that are now attained have never before been attained which may
be attributed to the following reasons,
-I
(a) The fireclay has not been burnt sufficiently.
(b) The fireclay has been mixed with other substances as silica and carbon in
different shapes & & which have made the sand fusible and caused sticking to the
surface of the castings.
(o) The fireclay has not been sufficiently pure and free from alkalies.
(d) The fireclay has not been sufficiently fireproof for some other reason,
(e) Blacking has been used on the surface of the moulds whereby the castings
have been made hard on the surface.
3
As to the results which have never been attained by anybody else there may be
mentioned that with the new facing sand it is possible to make castings of mild 4
steel and even of the softest wrought iron, the castings retaining their quality of
mild steel or soft iron without any kind of annealing or other treatment, the
castings being practically solid and their surface perfectly smooth and of a
beautiful appearance,

page_text: COMPLETE SPECIFICATION.
"
I THORSTEN NORDENFELT of 53 Parliament Street in the City of Westminster
Civil Engineer do hereby declare the nature of my invention for "IMPROVEMENTS
IN THE PRODUCTION OF IRON STEEL AND OTHER METAL CASTINGS A communi-
cation from abroad by Carl Gustaf Wittenström of Motala Edward Faustman and
Petter Östberg Civil Engineers of Stockholm all in the Kingdom of Sweden and in
what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:
This Invention has for its object, improvements in the production of iron steel
and other metal castings.
In the production of castings in sand moulds from metals having a high melting
point as iron and steel and especially iron nearly free from carbon the sand plays a
prominent part for obtaining a good and fine product.
A facing sand in every way suitable has never hitherto been produced. It
should be infusible so that it may not stick to the castings nor act in any way.
injuriously upon the metal.
.
After many experiments it has been found that hard burned fire clay mixed only
with binding material and a little liquid hydrocarbon to give a fine surface is the
most suitablo material.
I would here state that burnt fire clay has sometimes been used as an ingredient
in facing sand employed in the production of fine art castings in bronze but always
in admixturo with siliceous sand and usually with powdered charcoal.
Now such admixtures do not produce facing sands suitable for use with metals
requiring very high temperatures in the casting operation. The siliceous sand
fluxes the clay causing the sand to adhere to the face of the casting.
Powdered charcoal by combining with the metal tends to alter and deteriorate
the face of the casting especially if of comparatively puro iron or steel and its ash
also tends to render the facing sand less refractory.
The facing sand the subject of this specification is prepared solely from bard
burned fire clay finely ground with only so much binding substance added as to.
make it firm after drying. As binding substances sugar, molasses, gum, glue, raw.
clay etc etc can be used but sugar is preferred because it has been found superior,
and it is clean and of equal quality and may be had everywhere. To make the
facing sand leave the castings more easily and give the castings a fine looking
surface a small quantity of kerosene or like hydrocarbon oil is added.
Old furnace bricks of good fire clay well cleaned from glaze or the like give the
best and cheapest sand. The clay ought to be of the most fireproof kind and to be
as free from foreign ingredients as possible and specially from such as are of an
alkaline nature,

page_text: It has been found that different fire clays require different quantities of binding
substance to give the requisite firmness: the following proportions will generally
be found suitable:-One volume white crystallized sugar is dissolved in about
two volumes pure water and strained and then about one eighth of a volume of
kerosene or like hydrocarbon oil is added. Twenty four to thirty volumes of 5
hard burned powdered fireclay is moistened with the foregoing solution and the
mass passed through a coarse sieve several times so as to insure an equal dis-
tribution of the moisture. This facing sand ought to be as moist as common facing
sand and to this end more water is added if necessary. Care should be taken
to employ pure materials and especially such as are free from lime and like 1
impurities as these even when present in very small proportion injure the face of
the castings.
The facing sand the subject of this specification differs in its properties from
every other facing sand in the following viz.
1. It is practically infusible and therefore does not stick to the castings which 1
are found loose and clean when the mould is opened, and but insignificant cleaning
is required.
2. It does not appreciably carburate the castings as any sand containing carbon
-in any shape will do, neither will it make the castings porous-or-brittle, as the
silicon fncing band seems to do. The castings will preserve their nature of wrought-2
iron or steel according to the percentage of carbon in the molten metal.
3. It gives to the castings an exceedingly beautiful light-blue glossy surface.
4. Although fireclay may have been before used as an ingredient in facing sand
-the-same-results-that are now attained have never before been attained which may
be attributed to the following reasons.
(a). The facing sand has not been composed-almost entirely of burnt fire clay, but
this material has been mixed to a substantial and (when refractory metals have to
be dealt with) very injurious extent with other materials.
(b). The fire clay has not been burnt sufficiently.
-2
(c). The fire clay has been mixed with other substances as silica and carbon in 3
different shapes & & which have made the sand fusible and caused sticking to
the surface of the castings.
(d). The fire clay has not been sufficiently pure and free from alkalies.
(e). The fireclay has not been sufficiently fireproof for some other reason.
'
(f). Blacking has been used on the surface of the moulds whereby the castings 3
have been made hard on the surface.
As to the results which have never been attained by any body else there may be
mentioned that with the new facing sand it is possible to make castings of mild
steel and even of the softest wrought iron, the castings retaining their quality of
mild steel or soft iron without any kind of annealing or other treatment, the 4
castings being practically solid and their surface perfectly smooth and of a beautiful
appearance.
I call the sand to which this patent relates facing sand because for the sake of
economy the body of the mould will usually be made of a cheaper material and it is
sufficient if the face of the mould to the depth to which the sand is exposed to high 4
temperature be of this material. Nevertheless the entire mould may be made of my
facing sand.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
First. The use in the production of wrought iron steel and other metal castings
of a facing or moulding material consisting entirely of ground hard burnt fire clay
with only so much binding material as is absolutely necessary to hold the mould
together when dried.
6

page_text: Second. The use in the production of wrought iron steel and other metal castings
of a facing or moulding material consisting entirely of ground hard burnt fire clay
with only so much binding material as is absolutely necessary to hold the mould
together when dried and a small quantity of kerosene or like oil added.
Dated thin 10th 18- 100
"
CARPMAEL & Co.,
Agents for the Applicant.