Year: 1899

page_text: We, CARL GUSTAV MEISSNER, Proprietor of Iron Works, and ROBERT
BENNEWITZ, Engineer, both of 40, Augustastrasse, Magdeburg, in the German
Empire, do hereby declare the nature of this invention to be as follows:-
This invention relates to a process for hardening steel which on the one hand
imparts.a cutting hardness to the steel so that a retempering of the steel after
hardening, as is the case with ordinary processes, is not necessary, and on the
other hand prevents the bursting or fracture of the steel. After the steel is
sufficiently heated it is immersed in one bath only for cooling, the said bath
being composed of the following constituents, viz:-
About 3 parts of water, and
1 part of a mixture comprising about-
1 part by weight of zinc white
1 part by weight of charcoal dust
1 part by weight of leather liquor
1 part by weight of petroleum.
The three parts of water are intimately mixed with the one part of the above
mixture.
In this manner the steel has imparted to it an exceptional hardness; bursting
or fracturing of the steel is practically prevented and the cutting efficiency
of the steel is in nowise prejudiced.
There is no necessity to coat the steel with any substance, such as whitening
or varnish, before healing it.
Dated this 21st day of July 1899.
We, CARL GUSTAV MEISSNER, Proprietor of Iron Works, and ROBERT
BENNEWITZ, Engineer, both of 40, Augustastrasse, Magdeburg, in the German
Empire, 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:-
This invention relates to a process for hardening steel which on the one hand
imparts a cutting hardness to the steel so that a retempering of the steel after
hardening, as is the case with ordinary processes, is not necessary, and on the

page_text: other hand prevents the bursting or fracture of the steel. After the steel is
sufficiently heated it is immersed in one bath only for cooling, the said bath
being composed of the following constituents, viz:-
About 3 parts of water, and
1 part of a mixture comprising about--
1 part by weight of zinc white
1 part by weight of charcoal dust
part by weight of leather liquor
I part by weight of petroleum.
The three parts of water are intimately mixed with the one part of the above
mixture:
Leather liquor is a watery extract of new leather prepared with tan and can
be advantageously prepared as follows, that is to say, by boiling one kilogramme
of waste new leather (dressed with tan) with about 10 litres of water until the
waste leather is fully softened and leached by being allowed to remain in the
lye for about 24 hours so as to gradually cool down. The mass is then sifted
and the lye. then ready for use, can be barrelled.
In this manner the steel has imparted to it an exceptional hardness; bursting
or fracturing of the steel is practically prevented and the cutting efficiency
of the steel is in nowise prejudiced.
There is no necessity to coat the steel with any substance, such as whitening
or varnish, before heating it.
Having now particularly described asd ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. A process for hardening steel, such process consisting in cooling the heated
steel in a single bath composed of about three parts of water and one part of a
mixture consisting of about one part by weight each of zinc white, charcoal
dust, leather liquor and petroleuni whereby the requisite hardness is obtained
without retempering the steel, substantially as herein before described.
2. A composition for hardening steel consisting of a mixture of zinc white,
charcoal dust, leather liquor and petroleum in substantially the proportions
hereinbefore described.
n
11
1
1000
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.