Improvements in Materials for use in Cutting, Grinding, and Polishing, and in the Manufacture thereof.
Year: 1891

page_text: Date of Application, 2nd Mar., 1891
Complete Specification Left, 4th Jan., 1892-Accepted, 6th Feb., 1892
PROVISIONAL SPECIFICATION.
[Communicated from abroad by CHARLES MORTIMER LINDSEY, Marble and
Granite Worker, of Pittsburgh, Pennsylvania, United States of America.]
Improvements in Materials for use in Cutting, Grinding, and
Polishing, and in the Manufacture thereof.
1, JAMES JOHNSON of 4 Clayton Square, Liverpool, in the County of
Lancaster, Patent Agent do hereby declare the nature of this invention to be as
follows:-
:-
The object of my invention is to provide improved materials for cutting, grinding
and polishing, stone metal and other hard substances.
The invention consists
First. In reducing hardened steel by crushing or fracture to small regularly
shaped grains having the sharp corners and edges of natural fracture, such grains
forming the desired material.
Second. In reducing hardened steel by crushing or fracture to small particles
and in subsequently tempering such particles to obtain a grinding crushing and
polishing material of great toughness and durability.
J. JOHNSON.
COMPLETE SPECIFICATION.
Improvements in Materials for use in Cutting, Grinding, and
Polishing, and in the Manufacture thereof.
1 JAMES JOHNSON of 4 Clayton Square Liverpool in the County of
Lancaster Patent Agent do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The object of my invention is to provide improved materials for cutting, grinding,
and polishing stone, metal and other hard substances.
The invention consists :-
First. In reducing hardened steel by crushing or fracture to small regularly
shaped grains having the sharp corners and edges of natural fracture; such grains
forming the desired material.
Second. In reducing hardened steel by crushing or fracture to small particles
and in subsequently tempering such particles to obtain a grinding, crushing and
polishing material of great toughness and durability.
In carrying my invention into practice I take pieces of steel,-good crucible steel
is the best for the purpose and harden it, preferably by heating it to a temperature
of about 2500 degrees Fahrenheit sufficient to "burn" the steel, and quenching it
by plunging it in cold water, or in a tempering solution a suitable mixture for the
purpose being a solution of two quarts of common salt and one pound of soda in a
gallon of water. Such burning and hardening make the steel very hard and brittle,
giving it a crystalline granular structure. I then place the steel under a hammer
or crushing machine, and subject it to repeated blows until it is reduced to small
crystalline particles, which may be of various sizes, from the form of a fine
crystalline powder to that of granules, such as above mentioned. The steel particles
are then tempered in any suitable way, but preferably by the following node.
They are placed in a pan or in a receptacle of any other suitable form, and are
there heated to a temperature of about 450 degrees Fahrenheit, until the particles

page_text: change in appearance to a straw colour, and they are then cooled by subjecting
them to cold air, preferably forced upon the particles by means of a blast fan or
pump. This tempering changes not only the appearance of the particles, giving
them a dull metallic lustre, but also greatly improves their character, rendering
them tougher and much more able than before to resist the crumbling and reducing
action of grinding and cutting.
The particles either before or after the tempering may be separated into lots of
different sizes by passing them through proper sieves. After tempering, the
material is ready for use.
Such substance possesses many advantages. It is hard, very durable and
performs the work of cutting, grinding, and polishing very rapidly. Its manner of
use is similar to that practised with other substances of a like nature, for example,
the fine crystalline powder is used as emery powder is commonly used, and the
grains may be used with grinding-wheels, saws or otherwise.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is :-
First. As a new article of manufacture, a cutting, grinding, or polishing material
composed of tempered particles of fractured steel which has been crystallized by
heating to a "burnt" temperature and quenching; substantially as and for the
purposes described.
Second. As a new article of manufacture, a cutting, grinding or polishing material
composed of granules of fractured steel which has been crystallized by heating to
a "burnt"
temperature and quenching; substantially as and for the purposes
described.
D
1
CT
1045